MORKŪNAS, Zigmantas. Material Conditions of Man’s Creative Activity. Problemos, [S. l.], v. 11, p. 12–17, 1973. DOI: 10.15388/Problemos.1973.11.5502. Disponível em: https://test.zurnalai.vu.lt/problemos/article/view/5502. Acesso em: 27 oct. 2025.