S. Hemambika, K. Raghu Babu, and N. Annapurna. “Spectrophotometric Determination of Raltgravir Potassium and Galantamine Hydrobromide Pharmaceuticals Using Folin-Ciocalteu Reagent and Iron (II) - Orthophenanthraline As Chromogenic Agents”. International Journal of Research in Chemistry and Environment (IJRCE), vol. 7, no. 3, June 2017, pp. 46-53, http://www.ijrce.org/index.php/ijrce/article/view/220.