Shevelо VN, Оdarіch ON. Some questions of the theory of oscillation (non-oscillation) of the solutions of second order delay differential equations . Ukr. Mat. Zhurn. [Internet]. 1971 Jun. 29 [cited 2025 Dec. 5];23(4):507-15. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/8584