Idowu, Abioye Adesoye, et al. “Differential Transform Method for Solving Mathematical Model of SEIR and SEI Spread of Malaria”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 40, no. 1, July 2018, pp. 197-19, https://gssrr.org/JournalOfBasicAndApplied/article/view/9068.