Akhtar, Muhammad Naveed, Auhammad Tayyib, Tahira Tasneem, and Anjum Rashid Butt. “ABO Blood Group in Patients With Peptic Ulcer Disease: Association With Secretor Status”. Annals of King Edward Medical University 9, no. 3 (July 11, 2016). Accessed May 4, 2024. https://annalskemu.org/journal/index.php/annals/article/view/1351.