V. BLIZNIKAS. Über einigen Geometrischen Objekten des metrischen Linienelementraumes. Lithuanian Mathematical Journal, [S. l.], v. 1, n. 1-2, p. 17–26, 1961. DOI: 10.15388/LMJ.1961.19147. Disponível em: https://www.journals.vu.lt/LMJ/article/view/19147.. Acesso em: 3 may. 2024.