S.A. Shchogolev. “On the Reduction of the Linear System of the Differential Equations With Coefficients of Oscillating Type to the Triangular Kind in the Non-Resonant Case”. Bulletin of L.N. Gumilyov Eurasian National University. Mathematics, computer science, mechanics series 130, no. 1 (March 30, 2020): 82–92. Accessed December 27, 2024. https://bulmathmc.enu.kz/index.php/main/article/view/67.