1.
Maher A, Utkkina YA. The variant of the Goursat problem for the sixth order equation. Tamkang J. Math. [Internet]. 2006 Dec. 31 [cited 2024 Apr. 25];37(4):309-16. Available from: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/145