Ramu, G., A. Biksham Babu, Ch. Murali Krishna, S. Venkata Rao, and C. Rambabu. 2012. “Visible Spectrophotometric Methods for the Determination of Naratriptan Hydrochloride in Pure and Dosage Forms”. Asian Journal of Chemistry 24 (8):3517-20. https://asianpubs.org/index.php/ajchem/article/view/9440.