El-Bagary, R.I. et al. 2013. Development and validation of a reversed phase liquid chromatographic method for the determination of three Gliptins and Metformin in the presence of Metformin impurity (1-cyanoguanidine). European Journal of Chemistry. 4, 4 (Dec. 2013), 444–449. DOI:https://doi.org/10.5155/eurjchem.4.4.444-449.844.