ADAMCZEWSKI, Przemysław. Jusuf-bek Umaszew and the importance of the Caucasus for Polish intelligence services during World War II in view of documents kept in Polish archives in London. Studia z Dziejów Rosji i Europy Środkowo-Wschodniej, [S. l.], v. 55, n. 3, p. 57–73, 2020. DOI: 10.12775/SDR.2020.EN5.03. Disponível em: https://apcz.umk.pl/SDR/article/view/SDR.2020.EN5.03. Acesso em: 8 lip. 2025.