TSIVILEV, A. P. ON THE QUESTION OF THE HELIUM ABUNDANCE IN ORION A MEASURED BY RADIO RECOMBINATION LINES. AND THE PRIMORDIAL HELIUM ABUNDANCE. Одеські астрономічні публікації, [S. l.], v. 33, p. 18–21, 2020. DOI: 10.18524/1810-4215.2020.33.216303. Disponível em: http://oap.onu.edu.ua/article/view/216303. Acesso em: 5 груд. 2025.