V. MUTHULAKSHMI; R. MANJURAM. Interval Oscillation Criteria for Second-order Forced Delay Differential Equation with Riemann-Stieltjes Integral. International Journal of Mathematics And its Applications, [S. l.], v. 6, n. 1 - B, p. 281–295, 2018. Disponível em: http://ijmaa.in/index.php/ijmaa/article/view/924. Acesso em: 9 may. 2024.