G. Ramu, A. Biksham Babu, S. Venkata Rao, and C. Rambabu, “Extractive Spectrophotometric Determination of Ondansetron Hydrochloride in Pure and Dosage Forms by Using Alizarin Red-S and Bromothymol Blue”, ajc, vol. 23, no. 10, pp. 4621–4624, Aug. 2011.