1.
Petrovskii YB. Periodic solutions of Quasilinear Hyperbolic integro-differential equations of second order. Ukr. Mat. Zhurn. [Internet]. 1996 Nov. 25 [cited 2025 Apr. 13];48(11):1572-5. Available from:
https://umj.imath.kiev.ua/index.php/umj/article/view/5211