Kinjal R Patel; Laxman M Prajapati; Amit K Joshi; Mahammadali L Kharodiya; Jimish R Patel. Application of Chemometrics in Simultaneous Spectrophotometric Quantification of Etophylline and Theophylline: The Drugs With Same Chromophore: Chemometrics in Simultaneous Spectrophotometric Determination. Iran J Pharm Sci 2013, 9, 17-28.