MOˇSNA, Frantiˇsek. TRIGONOMETRIC FUNCTIONS – ONE POSSIBLE DEFINITION. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 36, p. 509–518, 2016. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/6602. Acesso em: 5 sep. 2026.