Abou-Dan, M., S. Ashour, and H. Abou-Dan. 2010. “Conductometric Titration of Metformin in Pure Form and in Pharmaceutical Preparations Using Sodium Tetraphenylborate and Cetylpyridinium Bromide”. Asian Journal of Chemistry 13 (1):1-7. https://asianpubs.org/index.php/ajchem/article/view/22518.