E. JAGATHPRABHAV; V. DHARMAIAH. Oscillations of delay differential equations with variable coefficients. Malaya Journal of Matematik, India, v. 8, n. 02, p. 489–493, 2020. DOI: 10.26637/MJM0802/0028. Disponível em: https://www.malayajournal.org/index.php/mjm/article/view/1438. Acesso em: 16 jul. 2024.