Forschung

Artikel in Fachzeitschriften

2018

• Ambrosius, M., Grimm, V., Sölch, C., & Zöttl, G. (2018). Investment Incentives For Flexible Demand Options Under Different Market Designs. Energy Policy, 118, 372 - 389. https://dx.doi.org/10.1016/j.enpol.2018.01.059
• Assembayeva, M., Egerer, J., Mendelevitch, R., & Zhakiyev, N. (2018). A spatial electricity market model for the power system: The Kazakhstan case study. Energy, 149, 762-778. https://dx.doi.org/10.1016/j.energy.2018.02.011
• Buschmann, B., Gärtner, D., Grimm, V., Osiander, C., & Stephan, G. (2018). Wann würden Frauen für Tarifkommissionen kandidieren? * Befunde aus einem faktoriellen Survey. Industrielle Beziehungen - Zeitschrift für Arbeit, Organisation und Management, 3, 320-342. https://dx.doi.org/10.3224/indbez.v25i3.03
• Cagala, T., Glogowsky, U., Grimm, V., & Rincke, J. (2018). Public Goods Provision with Rent-Extracting Administrators. Economic Journal. https://dx.doi.org/10.1111/ecoj.12614
• Friedl, A., Neyse, L., & Schmidt, U. (2018). Payment scheme changes and effort Adjustment: The role of 2D:4D digit ratio. The Journal of Behavioral Economics, 72, 86–94. https://dx.doi.org/10.1016/j.socec.2017.11.007
• Grimm, V., Grübel, J., Schewe, L., Schmidt, M., & Zöttl, G. (2018). Nonconvex Equilibrium Models for Gas Market Analysis: Failure of Standard Techniques and Alternative Modeling Approaches. European Journal of Operational Research. https://dx.doi.org/10.1016/j.ejor.2018.09.016
• Grimm, V., & Mengel, F. (2018). An Experiment on Belief Formation in Networks. Journal of the European Economic Association.
• Grimm, V., Schewe, L., Schmidt, M., & Zöttl, G. (2018). A multilevel model of the European entry-exit gas market. Mathematical Methods of Operations Research. https://dx.doi.org/10.1007/s00186-018-0647-z

2017

• Bartke, S., Friedl, A., Gelhaar, F., & Reh, L. (2017). Social comparison nudges—Guessing the norm increases charitable giving. Economics letters, 152, 73-75. https://dx.doi.org/10.1016/j.econlet.2016.12.023
• Choo, L., Kaplan, T.R., & Zultan, R. (2017). Information Aggregation in Arrow-Debreu Markets: An Experiment. Experimental Economics. https://dx.doi.org/10.1007/s10683-017-9548-x
• Drechsler, M., Egerer, J., Lange, M., Masurowski, F., Meyerhoff, J., & Oehlmann, M. (2017). Efficient and equitable spatial allocation of renewable power plants at the country scale. Nature energy, 2. https://dx.doi.org/10.1038/nenergy.2017.124
• Feicht, R., Grimm, V., Rau, H., & Stephan, G. (2017). On the impact of quotas and decision rules in collective bargaining. European Economic Review, 100, 175-192. https://dx.doi.org/10.1016/j.euroecorev.2017.08.004
• Friedl, A., Ring, P., & Schmidt, U. (2017). Gender differences in ambiguity aversion under different outcome correlation structures. Theory and Decision, 82(2), 211-219. https://dx.doi.org/10.1007/s11238-016-9565-9
• Grimalda, G., Bartke, S., Bosworth, S., Friedl, A., Lima de Miranda, K., Ring, P., & Snower, D. (2017). Exploiting behavioural insights to foster global cooperation. Economics : the Open-Access, Open-Assessment e-Journal, 101.
• Grimm, V., Ambrosius, M., Rückel, B., Sölch, C., & Zöttl, G. (2017). Modellierung von liberalisierten Strommärkten – Herausforderungen und Lösungen. Perspektiven der Wirtschaftspolitik, 18(1), 2 - 31. https://dx.doi.org/10.1515/pwp-2017-0001
• Grimm, V., Kleinert, T., Liers, F., Schmidt, M., & Zöttl, G. (2017). Optimal price zones in electricity markets: a mixed-integer multilevel model and global solution approaches. Optimization Methods & Software, 1-31. https://dx.doi.org/10.1080/10556788.2017.1401069
• Grimm, V., Schewe, L., Schmidt, M., & Zöttl, G. (2017). Uniqueness of market equilibrium on a network: A peak-load pricing approach. European Journal of Operational Research, 261(3), 971 - 983. https://dx.doi.org/10.1016/j.ejor.2017.03.036
• Grimm, V., Utikal, V., & Valmasoni, L. (2017). In-group favoritism and discrimination among multiple out-groups. Journal of Economic Behavior & Organization, 143, 254-271. https://dx.doi.org/10.1016/j.jebo.2017.08.015

2016

• Abraham, M., Grimm, V., Neeß, C., & Seebauer, M. (2016). Reputation formation in economic transactions. Journal of Economic Behavior & Organization, 121, 1-14. https://dx.doi.org/10.1016/j.jebo.2015.10.010
• Büttner, T., & Grimm, V. (2016). Taxation, social norms, and compliance: Research questions and results. Journal of Economic Behavior & Organization, 124, 1-6. https://dx.doi.org/10.1016/j.jebo.2016.02.004
• Choo, L., Fonseca, M.A., & Myles, G.D. (2016). Do students behave like real taxpayers in the lab? Evidence from a real effort tax compliance experiment. Journal of Economic Behavior & Organization, 124, 102–114. https://dx.doi.org/10.1016/j.jebo.2015.09.015
• Dieckmann, A., Grimm, V., Unfried, M., Utikal, V., & Valmasoni, L. (2016). On trust in honesty and volunteering among Europeans: Cross-country evidence on perceptions and behavior. European Economic Review. https://dx.doi.org/10.1016/j.euroecorev.2016.01.011
• Egerer, J., Gerbaulet, C., & Lorenz, C. (2016). European Electricity Grid Infrastructure Expansion in a 2050 Context. Energy Journal, 37(SI3), 101-124. https://dx.doi.org/10.5547/01956574.37.SI3.jege
• Egerer, J., Weibezahn, J., & Hermann, H. (2016). Two price zones for the German electricity market Market implications and distributional effects. Energy Economics, 59, 365-381. https://dx.doi.org/10.1016/j.eneco.2016.08.002
• Feicht, R., Grimm, V., & Seebauer, M. (2016). An experimental study of corporate social responsibility through charitable giving in Bertrand markets. Journal of Economic Behavior & Organization, 124, 88-101. https://dx.doi.org/10.1016/j.jebo.2015.11.005
• Grimm, V., Lang, J., & Stephan, G. (2016). Tarifverträge und die Lohnlücke zwischen Männern und Frauen Empirische Evidenz aus Zerlegungsanalysen. Industrielle Beziehungen - Zeitschrift für Arbeit, Organisation und Management, 23(2), 309-333.
• Grimm, V., Martin, A., Schmidt, M., Weibelzahl, M., & Zöttl, G. (2016). Transmission and generation investment in electricity markets: The effect of market splitting and network fee regimes. European Journal of Operational Research, 254(2), 493-509. https://dx.doi.org/10.1016/j.ejor.2016.03.044
• Grimm, V., Martin, A., Weibelzahl, M., & Zöttl, G. (2016). On the long run effects of market splitting: Why more price zones might decrease welfare. Energy Policy, 94, 453-467. https://dx.doi.org/10.1016/j.enpol.2015.11.010
• Grimm, V., Rückel, B., Sölch, C., & Zöttl, G. (2016). Zur Reduktion des Netzausbaubedarfs durch Redispatch und effizientes Engpassmanagement: Eine modellbasierte Abschätzung. List Forum für Wirtschafts- und Finanzpolitik, 41(4), 465-498. https://dx.doi.org/10.1007/s41025-016-0027-5
• Großer, J., & Seebauer, M. (2016). The curse of uninformed voting: An experimental study. Games and Economic Behavior, 97, 205-226. https://dx.doi.org/10.1016/j.geb.2016.04.009

2015

• Egerer, J., Rosellón, J., & Schill, W.-P. (2015). Power System Transformation toward Renewables: An Evaluation of Regulatory Approaches for Network Expansion. Energy Journal, 36(4), 105-128. https://dx.doi.org/10.5547/01956574.36.4.jege
• Gärtner, D., Grimm, V., Lang, J., & Stephan, G. (2015). Kollektive Lohnverhandlungen und der Gender Wage Gap: Befunde aus einer qualitativen Studie. Industrielle Beziehungen - Zeitschrift für Arbeit, Organisation und Management, 22(3/4), 260-281.
• Huppmann, D., & Egerer, J. (2015). National-strategic investment in European power transmission capacity. European Journal of Operational Research, 247(1), 191-203. https://dx.doi.org/10.1016/j.ejor.2015.05.056
• Schill, W.-P., Egerer, J., & Rosellón, J. (2015). Testing regulatory regimes for power transmission expansion with fluctuating demand and wind generation. Journal of Regulatory Economics, 47(1), 1-28. https://dx.doi.org/10.1007/s11149-014-9260-0
• Sproten, A., & Schwieren, C. (2015). Age differences in the reaction to incentives – A test of the successful ageing extension of Social Production Functions Theory. The Journal of the Economics of Ageing, 6, 176-186. https://dx.doi.org/10.1016/j.jeoa.2015.02.002

2013

• Bachmann, R., Braun, S., Friedl, A., Giesecke, M., Groll, D., Kramer, A.,... Sachs, A. (2013). Demografie und Wachstum: Die gesamtwirtschaftlichen Effekte einer höheren Erwerbstätigkeit Älterer. Zeitschrift für Wirtschaftspolitik, 62(3).
• Bolle, F., Grimm, V., Ockenfels, A., & del Pozo, X. (2013). An experiment on supply function competition. European Economic Review, 63, 170-185. https://dx.doi.org/10.1016/j.euroecorev.2013.06.006
• Egerer, J., Kunz, F., & Hirschhausen, C.v. (2013). Development scenarios for the North and Baltic Seas Grid - A welfare economic analysis. Utilities Policy, 27, 123-134. https://dx.doi.org/10.1016/j.jup.2013.10.002
• Grimm, V., & Ilieva, L. (2013). An experiment on emissions trading: the effect of different allocation mechanisms. Journal of Regulatory Economics, 44(3), 308-338. https://dx.doi.org/10.1007/s11149-013-9222-y
• Grimm, V., & Zöttl, G. (2013). Investment Incentives and Electricity Spot Market Competition. Journal of Economics & Management Strategy, 22(4), 832-851. https://dx.doi.org/10.1111/jems.12029

2012

• Engelmann, D., & Grimm, V. (2012). Mechanisms for Efficient Voting with Private Information about Preferences. Economic Journal, 122(563), 1010-1041. https://dx.doi.org/10.1111/j.1468-0297.2012.02515.x
• Grimm, V., & Mengel, F. (2012). An experiment on learning in a multiple games environment. Journal of Economic Theory, 147(6), 2220-2259. https://dx.doi.org/10.1016/j.jet.2012.05.011

2011

• Grimm, V., & Mengel, F. (2011). Let me sleep on it: Delay reduces rejection rates in ultimatum games. Economics letters, 111(2), 113-115. https://dx.doi.org/10.1016/j.econlet.2011.01.025
• Grimm, V., & Mengel, F. (2011). Matching technology and the choice of punishment institutions in a prisoner’s dilemma game. Journal of Economic Behavior & Organization, 78(3), 333-348. https://dx.doi.org/10.1016/j.jebo.2011.01.018

2010

• Grimm, V., & Zöttl, G. (2010). Price Regulation under Demand Uncertainty. B E Journal of Theoretical Economics, 10(1), 589-605. https://dx.doi.org/10.2202/1935-1704.1626

2009

• Engelmann, D., & Grimm, V. (2009). Bidding Behaviour in Multi-Unit Auctions – An Experimental Investigation. The Economic Journal, 119(537), 855-882. https://dx.doi.org/10.1111/j.1468-0297.2009.02249.x
• Grimm, V., & Mengel, F. (2009). Cooperation in viscous populations - experimental evidence. Games and Economic Behavior, 66(1), 202–220. https://dx.doi.org/10.1016/j.geb.2008.05.005
• Grimm, V., Schmidt, U., & Weber, M. (2009). Optimales Bietverhalten in Auktionen. Wirtschaftswissenschaftliches Studium, 38(8), 413-418. https://dx.doi.org/10.15358/0340-1650-2009-8-413

2008

• Grimm, V., Kovarik, J., & Ponti, G. (2008). Fixed price plus rationing: an experiment. Experimental Economics, 11(4), 402-422. https://dx.doi.org/10.1007/s10683-007-9184-y
• Grimm, V., Ockenfels, A., & Zöttl, G. (2008). Ein Vergleich ausgewählter europäischer Strombörsen. Zeitschrift für Energiewirtschaft, 32(3), 162–170. https://dx.doi.org/10.1007/s12398-008-0021-6
• Grimm, V., Ockenfels, A., & Zöttl, G. (2008). Strommarktdesign: Zur Ausgestaltung der Auktionsregeln an der EEX. Zeitschrift für Energiewirtschaft, 32(3), 147–161. https://dx.doi.org/10.1007/s12398-008-0020-7

2007

• Grimm, V. (2007). Book Review: An Introduction to the Structural Econometrics of Auction Data (by H. Paarsch and H. Hong). Journal of Economics, 92(2), 205-208. https://dx.doi.org/10.1007/s00712-006-0249-8
• Grimm, V. (2007). Sequential versus Bundle Auctions for Recurring Procurement. Journal of Economics, 90(1), 1-27. https://dx.doi.org/10.1007/s00712-006-0225-3

2006

• Bierbaum, J., & Grimm, V. (2006). Selling shares to retail investors: auction vs. fixed price. Review of Economic Design, 10(2), 85-112. https://dx.doi.org/10.1007/s10058-006-0007-y

2005

• Grimm, V., & Engelmann, D. (2005). Overbidding in First Price Private Value Auctions: Implications of a Multi-Unit Auction Experiment. Springer.

2004

• Grimm, V., Riedel, F., & Wolfstetter, E. (2004). The third generation (UMTS) spectrum license auction in Germany. In G. Illing (Eds.), Spectrum Auctions and Competition in Telecommunication (pp. 223-246). Cambridge, MA: MIT Press.

2003

• Grimm, V., Riedel, F., & Wolfstetter, E. (2003). Implementing efficient market structure. Review of Economic Design, 7(4), 443-463. https://dx.doi.org/10.1007/s100580300087
• Grimm, V., Riedel, F., & Wolfstetter, E. (2003). Low price equilibrium in multi-unit auctions: the GSM spectrum auction in Germany. International Journal of Industrial Organization, 21(10), 1557 - 1569. https://dx.doi.org/10.1016/S0167-7187(03)00058-4

2000

• Grimm, V., & Schmidt, U. (2000). Equilibrium Bidding without the Independence Axiom: A Graphical Analysis. Theory and Decision, 49(4), 361-374. https://dx.doi.org/10.1023/A:1026585831556
• Grimm, V., & Schmidt, U. (2000). Revenue equivalence and income taxation. Journal of Economics and Finance, 24(1), 56-63. https://dx.doi.org/10.1007/BF02759695

1999

• Grimm, V., & Schmidt, U. (1999). Optimale Auktionen. Wirtschaftswissenschaftliches Studium, 28(12), 670-675.

 

Revise & Resubmit

• Cagala, T., U. Glogowski, V. Grimm, J. Rincke, and A. Tuset (2017). Does Corruption Affect the Private Provision of Public Goods?. Mimeo, FAU Erlangen-Nürnberg, R&R Journal of Economic Behavior and Organization. https://dx.doi.org/10.2139/ssrn.3112049
• Büttner, T., V. Grimm, and K. Erbe (2018). Tax Planning of Married Couples and Intra-Household Income Inequality. Mimeo, FAU Erlangen-Nürnberg, R&R Journal of Public Economics. https://dx.doi.org/10.2139/ssrn.3016803
• Abraham, M., V. Grimm, K. Lorek, K. Möslein, C. Niessen, C. Schnabel, and M. Wrede (2018). To track or not to track?. Mimeo, FAU Erlangen-Nürnberg, R&R Human Ressource Management Journal.
• Runge, P., C. Sölch, J. Albert, P. Wasserscheid, G. Zöttl, and V. Grimm (2018). Economic comparison of different electric fuels for energy scenarios in 2035. Working Paper, FAU Erlangen-Nürnberg, R&R Applied Energy.
• Großer, J., & Seebauer, M. (2017). Standing versus ad hoc committees with costly information acquisition, R&R. Experimental Economics.

 

 

Working Papers

2018

• Büttner, T., Grimm, V., & Erbe, K. (2018). Tax Planning of Married Couples and Intra-Household Income Inequality.
• Grimm, V., Martin, A., Sölch, C., Weibelzahl, M., & Zöttl, G. (2018). Market-based Redispatch May Result in Inefficient Dispatch.
• Grimm, V., Rückel, B., Sölch, C., & Zöttl, G. (2018). The Impact of Market Design on Transmission and Generation Investment in Electricity Markets.
• Kretschmer, S., Grimm, V., & Mehl, S. (2018). Diffusion of Green Innovations: Evidence from a Field Study on Domestic Electricity Storage.

2017

• Abraham, M., Grimm, V., Lorek, K., Möslein, K., Niessen, C., Schnabel, C., & Wrede, M. (2017). To track or not to track? LASER Discussion Paper, No. 101, Erlangen-Nürnberg. Nürnberg.
• Cagala, T., Glogowsky, U., Grimm, V., Rincke, J., & Tuset Cueva, A. (2017). Does Corruption Affect the Private Provision of Public Goods?
• Doll, M., Seebauer, M., & Tonn, M. (2017). Bargaining over waiting time in gain and loss framed ultimatum games.
• Grimm, V., Casal, S., & Schächtele, S. (2017). Tax compliance with mobile high-income agents. An experiment on acceptance of regressive tax rates.
• Grimm, V., Grübel, J., Rückel, B., Sölch, C., & Zöttl, G. (2017). Analysis of Market Mechanisms to Coordinate Economic Activities in Smart Grids.
• Grimm, V., Rückel, B., Sölch, C., & Zöttl, G. (2017). Regionally differentiated network fees to provide proper incentives for generation investment.
• Großer, J., & Seebauer, M. (2017). Standing versus ad hoc committees with costly information acquisition, R&R Experimental Economics.
• Hafner, L., Reif, S., & Seebauer, M. (2017). Physician Behavior under Prospective Payment Schemes Evidence from artefactual field and lab experiments.

2016

• Choo, L., Grimm, V., Horvath, G., & Nitta, K. (2016). Remuneration Structure and Whistleblowing Behaviour: An Experimental Investigation.
• Choo, L., Grimm, V., Horvath, G., & Nitta, K. (2016). Whistleblowing and Diffusion of Responsibility: An Experimental Investigation.
• Drichoutis, A., Grimm, V., Karakostas, A., & Zhurakhovska, L. (2016). Queue Jumping.
• German, R., Götz, K., Grimm, V., Kufner, A., Leepa, C., Luther, M.,... Veerashekar, K. (2016). Virtueller Großspeicher zur Erbringung von Primärregelleistung – Pilotprojekt SWARM.
• Grimm, V., Grübel, J., Martin, S., & Zöttl, G. (2016). Distribution network modeling in electricity market environment.

2015

• Cagala, T., Glogowsky, U., Grimm, V., & Sproten, A. (2015). Efficiency Concerns with Non-Monetary Incentives.
• Engelmann, D., Grimm, V., & Tonn, M. (2015). Mechanisms to improve cooperation in a social dilemma under incomplete information.
• Friedl, A., Görlich, D., Horn, S., Krieger-Boden, C., & Lücke, M. (2015). How to Deal with Inequality Welfare System Challenges and European Responses.
• German, R., Götz, K., Grimm, V., Kufner, A., Leepa, C., Luther, M.,... Veerashekar, K. (2015). SWARM - Successful Provision of Frequency Containment Reserve with Distributed Energy Storage Systems.
• Seebauer, M. (2015). Does Direct Democracy Foster Efficient Policies? An Experimental Investigation of Costly Initiatives.

2013

• Engelmann, D., Grimm, V., & Tonn, M. (2013). On Bargaining under Incomplete Information.

2011

• Grimm, V., & Leepa, C. (2011). Determinants of Contract Awarding in Non-Binding Auctions.

2008

• Grimm, V. (2008). Cournot Competition under Uncertainty.

2005

• Grimm, V., & Zöttl, G. (2005). Access to Commitment Devices Reduces Investment Incentives in Oligopoly.
• Grimm, V., & Zöttl, G. (2005). Strategic Capacity Choice under Uncertainty: The Impact of Market Structure on Investment and Welfare.

2004

• Grimm, V. (2004). On Procurement Auctions of Complementary Goods.

2003

• Grimm, V., & Engelmann, D. (2003). Bidding Behavior in Multi-Unit Auctions - An Experimental Investigation and some Theoretical Insights.

2002

• Bierbaum, J., & Grimm, V. (2002). Uniform Price Auction vs. Fixed Price Mechanisms: A Numerical Analysis.
• Grimm, V., & Rupp, B. (2002). Automated Bandtwidth Exchange.

 

 

Gutachten

• Regionalkomponenten bei der EE-Vergütung. Gutachten im Auftrag der Monopolkommission in Vorbereitung des 77. Sondergutachtens Energie2017 der Monopolkommission. V. Grimm, G. Zöttl und C. Sölch (2017) Gutachten, Sondergutachten Energie2017
• Dezentralität und Zellulare Optimierung – Auswirkungen auf den Netzausbaubedarf. Gutachten im Auftrag der N-Ergie AG, V. Grimm, G. Zöttl, M. Ambrosius, B. Rückel und C. Sölch gemeinsam mit der Prognos AG (2016) Gutachten: Kurzfassung, Langfassung
• Regionale Preiskomponenten im Strommarkt. Gutachten im Auftrag der Monopolkommission in Vorbereitung des 71. Sondergutachtens Energie2015 der Monopolkommission. V. Grimm, G. Zöttl, B. Rückel und C. Sölch (2015) Gutachten, Sondergutachten Energie2015
• Stärkung von Investitionen in Deutschland. Bericht der Expertenkommission im Auftrag des Bundesministers für Wirtschaft und Energie, Berlin. Kommission: Fratzscher, M. (Vorsitz) , S. Articus, F. Bsirske, R. Feiger, L. P. Feld, J. Fitschen, V. Grimm, R. Hoffmann, H. Jung, M. Kerber, W. Lemb, F.-J. Lersch-Mense, H.-H. Loewenstein , T. Mayer, T. Oletzky, S. Russwurm, M. Schnitzer, U. Schröder, H. Schwager, E. Schweitzer, M. Vassiliadis, T. R. Böger, F. Nauschnigg, T. Posselt, A. Bender, W. Eckart, S. Eide, D. Homann, A. Lieber, L. Schuknecht, B. Alm, R. L ́Hoest, M. Meurers, U. Neuhäußer, P. Steinberg, S. Weins, J. Zettelmeyer, M. Gornig, C. Michelsen, B. Pagel, and A. Schiersch (2015) Bericht
• Strommarktdesign – Preisbildungsmechanismus im Auktionsverfahren fuer Stromstundenkontrakte an der EEX, Cologne. A. Ockenfels, V. Grimm und G. Zöttl (2008) Gutachten

 
 

Andere Publikationen

• Abraham, M., & Grimm, V. (2017). Reputation in Wirtschaftsbeziehungen: Empirische Befunde. In Maurer, A. (Eds.), Handbuch der Wirtschaftssoziologie (pp. 257-274). Wiesbaden: Springer VS.

• Ambrosius, M., Grimm, V., Sölch, C., & Zöttl, G. (2016). Investment incentives for flexible energy consumption in the industry. In IEEE (Eds.), 2016 13th International Conference on the European Energy Market (EEM) (pp. 1-5). Porto, PT.

• Grimm, V., & Zöttl, G. (2015). Investitionsanreize im Strommarkt der Zukunft. In Wolfgang Lemb (Eds.), Welche Industrie wollen wir? Nachhaltig produzieren - zukunftsorientiert wachsen. Frankfurt am Main: Campus.

• Grimm, V. (2007). Book Review: An Introduction to the Structural Econometrics of Auction Data (by H. Paarsch and H. Hong). Journal of Economics, 92(2), 205-208. https://dx.doi.org/10.1007/s00712-006-0249-8

• Grimm, V. (2003). Three Essays on Mechanism Design and Multi-Object Auctions. Aachen: Shaker Verlag.

• Grimm, V., Schmidt, U., & Weber, M. (2003). Auktionen: zu viel oder zu wenig geboten? In Forschung für die Praxis University of Mannheim.

• Grimm, V. (1999). Auction theory: a survey. In S. B. Dahiya (Eds.), The Current State of Economic Science Rothak: Spellbound Publications.