Nie%C3%9Fen%2C D.%2C Groskurth%2C K.%2C Kemper%2C C. J.%2C Rammstedt%2C B.%2C %26 Lechner%2C C. M. Optimism%E2%80%93Pessimism Short Scale%E2%80%932 %28SOP2%29.
Zusammenstellung sozialwissenschaftlicher Items und Skalen (ZIS). 2022;
Available from: https://zis.gesis.org/DoiId/10.6102%2Fzis322_exz