BULGÁKOV, Mikhail. Letter to the USSR Government. Opiniães, São Paulo, Brasil, n. 22, p. 532–538, 2023. DOI: 10.11606/issn.2525-8133.opiniaes.2023.212499. Disponível em: https://www.journals.usp.br/opiniaes/article/view/212499.. Acesso em: 18 may. 2024.