KAVALIAUSKAS, S. New Dissertations. Problemos, [S. l.], v. 12, p. 127–134, 1973. DOI: 10.15388/Problemos.1973.12.5532. Disponível em: https://www.journals.vu.lt/problemos/article/view/5532.. Acesso em: 27 sep. 2024.