Ademola, A. T., Peter Olutola Arawomo, and A. S. Idowu. 2017. “Stability, Boundedness and Periodic Solutions to Certain Second Order Delay Differential Equations.”. Proyecciones (Antofagasta, On Line) 36 (2):257-82. https://doi.org/10.4067/S0716-09172017000200257.