Amadi, C., and E. P. Odum. “Age-Specific Serum Prostate-Specific Antigen References Range Among Healthy Men in Port Harcourt, Nigeria: A Retrospective Hospital-Based Study”. International Journal of Research in Medical Sciences, vol. 6, no. 2, Jan. 2018, pp. 417-21, doi:10.18203/2320-6012.ijrms20180278.