Payal Kate, Parag Patel, Nikita Patel, Gaurav Kulkarni, and Bhawan Kumar Patel, “Stability indicating RP-HPLC method development and validation of Etizolam and Propranolol hydrochloride in pharmaceutical dosage form”, World J Pharm Sci, vol. 3, no. 6, pp. 1113–1124, Jun. 2015.