ŠIRKA, J. Three grades of technical olympiad. Journal of Education, Technology and Computer Science, [S. l.], v. 7, n. 1, p. 88–92, 2013. DOI: 2080-9069. Disponível em: https://journals.ur.edu.pl/jetacomps/article/view/6812. Acesso em: 24 sie. 2024.