S. . Bejrachandra, O. . Nathalang, J. Saipin, S. . Kuvanont, K. . Wichitchinda, and A. . Vongpattranon, “Distribution of Blood Group Systems in Thai Blood Donors Determined by the Gel Test”, Siriraj Med J, vol. 54, no. 7, pp. 403–409, Jul. 2002.