N. H. EL – HAMMAMY, A. I. KAWANA, M. F. AMIRA, and N. S. EL – SISY. 2010. “Electrical Conductivity and Ion Pair Formation of S-Acetylthiocholine Halides and Perchlorate in Ethanol - Water At 25 Oc”. International Journal of Pharma and Bio Sciences 1 (2):1-13. https://ijpbs.net/index.php/journal/article/view/195.