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).
https://doi.org/10.6102%2Fzis322_exz