Paul, Nsirimobu Ichendu, and Oliemen Peterside. “Hepatitis B Vaccination Rate Among Medical Students at the University of Port Harcourt Teaching Hospital (UPTH), Nigeria”. The Nigerian Health Journal, vol. 14, no. 2, Dec. 2015, p. 64, https://tnhjph.com/index.php/tnhj/article/view/160.