Mayer, Franz. 2020. “The Ultra Vires Ruling: Deconstructing the German Federal Constitutional Court's PSPP decision of 5 May 2020”. European Constitutional Law Review 16 (4): 733-769.
Mayer, Franz. 2013. “Constitutional comparativism in action. The example of general principles of EU law and how they are made-a German perspective”. International Journal of Constitutional Law 11 (4): 1003-1020.