Khanum, Ayesha, Saima Farhan, Nazish Saqlain, and Sundas Arshad. “Prevalence of A2 and A2B Subgroups Among Blood Groups A and AB in Healthy Donors”. Pakistan Journal of Medical Sciences 40, no. 1 (November 16, 2023). Accessed February 25, 2024. https://www.pjms.org.pk/index.php/pjms/article/view/7916.