Erzin, Alexandr, Zuzanna Gazdowska, and Małgorzata Piotrowska-Półrolnik. 2017. “When ‘social Existence Determines consciousness’: The Influence of Political System on Psychological Well-Being, Happiness, Proactive Coping, and Depression Levels Among Polish and Russian Citizens – a Cross-Cultural Study”. Journal of Education, Health and Sport 7 (4):342-59. https://apcz.umk.pl/JEHS/article/view/4381.