1.
Kostin AV, Shchegolev SA. On solutions of a second-order quasilinear differential system representable by Fourier series with slowly varying parameters. Ukr. Mat. Zhurn. [Internet]. 1998May25 [cited 2024Nov.24];50(5):654–664. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/4903