SUNDAR SANTRA S. Necessary and sufficient conditions for oscillation of second-order differential equation with several delays. Stud. Univ. Babeş-Bolyai Math. [Internet]. 2023 Jun. 14 [cited 2025 Feb. 5];68(2):319-30. Available from: https://studia.reviste.ubbcluj.ro/index.php/subbmathematica/article/view/6003