Tavallali H, Salami M. Simultaneous Determination of Caffeine and Paracetamol by Zero-Crossing Second Derivative Spectrophotometry in Pharmaceutical Preparations. ajc [Internet]. 2010 Mar. 30 [cited 2024 Nov. 29];21(3):1949-56. Available from: https://asianpubs.org/index.php/ajchem/article/view/18682