Ortmann, Regina, and Erich Pummerer. “Distortional Effects of Separate Accounting and Formula Apportionment on Factor Allocation.”https://doi.org/10.1007/s11573-022-01133-5__Journal of Business Economics, 2023.https://doi.org/10.1007/s11573-022-01133-5 .

Ortmann, Regina, and Dirk Schindler. Income Shifting and Management Incentives. TAF Working Paper Serie, 2022.

Warkulat, Sonja, Sebastian Krull, Regina Ortmann, Nina Klocke, and Matthias Pelster. “COVID-19 Reporting and Willingness to Pay for Leisure Activities.” Covid Economics, no. 83 (2021): 183–205.

Ortmann, Regina, Sonja Warkulat, Sebastian Krull, Nina Klocke, and Matthias Pelster. COVID-19 Reporting and Willingness to Pay for Leisure Activities. Vol. 83. Working Paper in Covid Economics: Vetted and REal-Time Papers, 2021.

Ortmann, Regina, Dirk Simons, and Dennis Voeller. Real Effects of an International Tax Reform for MNEs. Vol. 64. TRR 266 Working Paper Series, 2021.

Ortmann, Regina, Matthias Pelster, and Sascha Tobias Wengerek. “COVID-19 and Investor Behavior.”https://doi.org/10.1016/j.frl.2020.101717__Finance Research Letters 37 (2020).https://doi.org/10.1016/j.frl.2020.101717 .

Ortmann, Regina, Matthias Pelster, and Sascha Tobias Wengerek. “COVID-19 and Investor Behavior.”https://doi.org/10.1016/j.frl.2020.101717__Finance Research Letters 37 (2020).https://doi.org/10.1016/j.frl.2020.101717 .

Ortmann, Regina, and Caren Sureth-Sloane. “Can the CCCTB Alleviate Tax Discrimination against Loss-Making European Multinational Groups?”https://doi.org/10.1007/s11573-015-0780-6__Journal of Business Economics 86, no. 5 (2016): 441–75.https://doi.org/10.1007/s11573-015-0780-6 .

Ortmann, Regina, and Caren Sureth-Sloane. “Can the CCCTB Alleviate Tax Discrimination against Loss-Making European Multinational Groups?”https://doi.org/10.1007/s1007-015-0780-6__Journal of Business Economics 86, no. 5 (2016): 441–75.https://doi.org/10.1007/s1007-015-0780-6 .

Ortmann, Regina. Uncertainty in Weighting Formulary Apportionment Factors. How Does Weighting Uncertainty Impact After-Tax Income of Multinational Groups?,. Vol. 2015–10. WU Working Paper Series, 2015.

Ortmann, Regina. Uncertainty in Weighting Formulary Apportionment Factors and Its Impact on After-Tax Income of Multinational Groups. Vol. 198. Arqus - Quantitative Research in Taxation, 2015.

Ortmann, Regina. “Uncertainty in Weighting Formulary Apportionment Factors.” Die Betriebswirtschaft 75, no. 3 (2015): 161–77.

Ortmann, Regina, and Caren Sureth-Sloane. Can the CCCTB Alleviate Tax Discrimination against Loss-Making European Multinational Groups? Vol. 165. Arqus, Quantitative Research in Taxation, 2014.