ARUSHANYAN, O.; ZALETKIN, S. To the orthogonal expansion theory of the solution to the Cauchy problem for second-order ordinary differential equations. Numerical Methods and Programming (Vychislitel’nye Metody i Programmirovanie), [S. l.], v. 19, n. 56, p. 178–184, 2018. DOI: 10.26089/NumMet.v19r216. Disponível em: https://en.num-meth.ru/index.php/journal/article/view/963. Acesso em: 14 dec. 2025.