Igboamalu, Chukwunonso, and Daprim Ogaji. “Knowledge, Attitude, and Practice of Patient Referral Among Patent and Proprietary Medicine Vendors in Obio-Akpor, Rivers State”. Nigerian Medical Journal 65, no. 4 (September 26, 2024): 443–455. Accessed June 8, 2026. https://www.nigerianmedjournal.org/index.php/nmj/article/view/417.