P. Salomi, D. M. Nayak, T. Vimalakannan, and K. R. Reddy, “Method development and method validation of guaifenesin and dextromethorphan by RP-HPLC”, Int. Jrnl.. Res. Pharm. Chem. & Analy, vol. 1, no. 1, pp. 18-24, Jun. 2018.