S. P. Vassa, P. P. Vairagar, S. V. Mulgund, and R. V. Korhale, “RP-HPLC Method Development And Validation For Simultaneous Estimation Of Ramipril And S (-) Amlodipine In Tablet Dosage Form”, Asian J Pharm Res Dev, vol. 1, no. 4, pp. 81–87, Jul. 2013.