SAPARWADI, L. Kestabilan Titik Ekuilibrium Bebas Heroin dalam Model Sistem Persamaan Diferensial (ODE). Beta: Jurnal Tadris Matematika, [S. l.], v. 4, n. 2, p. 133–150, 2011. Disponível em: https://jurnalbeta.ac.id/index.php/betaJTM/article/view/76. Acesso em: 15 aug. 2026.