Singh Gill, D.M.P. 2013. Comparative Study of Serum Gamma Glutamyltransferase, 5’ Nucleotidase and Alkaline Phosphatase in Icteric and an-Icteric Biliary Disease Patients. IIUM Medical Journal Malaysia. 12, 1 (Jun. 2013). DOI:https://doi.org/10.31436/imjm.v12i1.2004.