1. Agarwal, R.P., Grace, S.R., O’Regan, D.: Oscillation Theory for Difference and Functional Differential Equations. Kluwer Academic, Dordrecht (2000)
2. Agarwal, R.P., Grace, S.R., O’Regan, D.: Oscillation Theory for Second Order Dynamic Equations. Taylor & Francis, London (2003)
3. Agarwal, R.P., Berezansky, L., Braverman, E., Domoshnitsky, A.: Nonoscillation Theory of Functional Differential Equations with Applications. Springer, New York (2012)
4. Bohner, M., Sudha, B., Tangavelu, K., Thandapani, E.: Oscillation criteria for second-order differential equations with superlinear neutral term. Nonlinear Stud. 26(2), 425–434 (2019)
5. Erbe, L.H., Kong, Q., Zhang, B.G.: Oscillation Theory for Functional Differential Equations. Marcel Dekker, New York (1995)