L.H, Gam, and Aishah Latiff. 2006. “Tandem Mass Spectrometric Analysis of Glycopeptides Derived from the Tryptic Digestion of Human Chorionic Gonadotropin (hCG)”. Malaysian Journal of Science 25 (2):87-95. http://ojie.um.edu.my/index.php/MJS/article/view/8129.