Heun Method Using to Solve System of NonLinear Functional Differential Equations. مجلة بغداد للعلوم, Iraq, Baghdad, v. 4, n. 4, p. 666–669, 2021. DOI: 10.21123/bsj.2007.4.4.666-669. Disponível em: https://bsj.uobaghdad.edu.iq/index.php/BSJ/article/view/852.. Acesso em: 18 2024.