[1]
Ptashnik Π’. I., β€œAn analogue of the $n$-point problem for a linear hyperbolic equation ”, Ukr. Mat. Zhurn., vol. 23, no. 4, pp. 472–480, Jun. 1971, Accessed: Feb. 17, 2026. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/8581