JWAMER, Karwan H.F.; RASUL, Rando R. Q. A comparison between the fourth order linear differential equation with its boundary value problem. Bulletin of the Karaganda University. Mathematics Series, [S. l.], v. 99, n. 3, p. 18–25, 2020. DOI: 10.31489/2020m3/18-25. Disponível em: http://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/376. Acesso em: 5 sep. 2025.