VASIL'EVA, Natal'ja Sergeevna. Alf Ross on the concept of law and legal validity: the realistic approach. Pravovedenie, [S. l.], v. 62, n. 1, p. 84–117, 2018. DOI: 10.21638/11701/spbu25.2018.105. Disponível em: https://pravovedenie.spbu.ru/article/view/6017. Acesso em: 5 may. 2024.