Mathematical model of competition in the educational services market. Journal on studies and research of academic knowledge, Itapúa, PY, n. 20, p. e2026008, 2026. DOI: 10.70833/rseisa20item778. Disponível em: https://revistas.uni.edu.py/index.php/rseisa/article/view/778. Acesso em: 2 apr. 2026.