SOLOVJOVAS, Nikolajus. Prognoses and Social Planning. Problemos, [S. l.], v. 7, p. 109–114, 1971. DOI: 10.15388/Problemos.1971.7.5819. Disponível em: https://test.zurnalai.vu.lt/problemos/article/view/5819. Acesso em: 25 oct. 2025.