P. Maczka, A. Gumieniczek, J. Galeza, and R. Pietras, “Zero crossing and ratio spectra derivative spectrophotometry for the dissolution tests of amlodipine and perindopril in their fixed dose formulations”, Curr. Issues Pharm. Med. Sci., vol. 27, no. 2, pp. 113–117, Nov. 2014, doi: 10.2478/cipms-2014-0027.