Robert Ganian, Sebastian Ordyniak, C. S. Rahul. Group Activity Selection with Few Agent Types. 27th Annual European Symposium on Algorithms, ESA 2019, September 9-11, 2019, Munich/Garching, Germany (Michael A. Bender, Ola Svensson, Grzegorz Herman, eds.), pages 48:1–48:16, 2019.