KERA, Samet; TRENČEVSKI, Kostadin. ON SOME CHARACTERISTIC SUBGROUPS OF THE GROUP OF UPPER TRIANGULAR MATRICES. Matematichki Bilten, [S. l.], v. 23, n. 1, p. 25–32, 1999. Disponível em: https://bilten.smm.org.mk/index.php/bilten/article/view/1594. Acesso em: 14 aug. 2026.