NARKEVIČIENĖ, Bronė; PAPRECKIENĖ, Laima. Competitive tasks in trigonometry: problematic aspect. Lietuvos matematikos rinkinys, [S. l.], v. 43, n. spec., p. 381–383, 2003. DOI: 10.15388/LMR.2003.32458. Disponível em: https://www.journals.vu.lt/LMR/article/view/32458.. Acesso em: 17 may. 2024.