Ezechukwu, C. C., C. E. Ezeudu, N. Obichukwu, S. Ameh, and A. Egbuogu. “ Nigeria: Risk Factors of Preterm Delivery and Its Prevalence in a Tertiary Hospital”. Tropical Journal of Medical Research, vol. 21, no. 2, Nov. 2022, pp. 49-55, doi:10.5281/zenodo.7794785.