MAZĖTIS, Edmundas; MELNIČENKO, Grigorijus. A rational cotangents of the angles of a triangle. Lietuvos matematikos rinkinys, [S. l.], v. 55, n. B, p. 84–89, 2014. DOI: 10.15388/LMR.B.2014.16. Disponível em: https://www.journals.vu.lt/LMR/article/view/17214.. Acesso em: 29 apr. 2024.