Venkata Kumar Ch, Nagamalleswara Rao K, Madhuri K, Anil Kumar Ch, and Kesava Rao T KV. “A Quantitative Determination of Penbutolol and Its Metabolite in Plasma by Liquid Chromatography Tandem Mass and Its Application to Pharmacokinetic Studies”. World Journal of Pharmaceutical Sciences 2, no. 2 (February 5, 2014): 149–160. Accessed June 28, 2025. https://www.wjpsonline.com/index.php/wjps/article/view/determination-penbutolol-metabolite-plasma-lcmsms.