С.А. Щёголев. “On the Reduction of the Linear System of the Differential Equations to the Bi-Diagonal Kind”. BULLETIN OF THE L.N. GUMILYOV EURASIAN NATIONAL UNIVERSITY. Mathematics. Computer science. Mechanics series 128, no. 3 (January 22, 2023): 34–45. Accessed May 18, 2024. https://bulmathmc.enu.kz/index.php/main/article/view/52.