Klassen, L., E. F. Eifler, A. Hufer, and R. Riemann. “WHY DO PEOPLE DIFFER IN THEIR ACHIEVEMENT MOTIVATION? A NUCLEAR TWIN FAMILY STUDY”. Primenjena Psihologija, vol. 11, no. 4, Jan. 2019, pp. 433-50, doi:10.19090/pp.2018.4.433-450.