Kardos, Peter, Walter Lehmacher, Andrea Zimmermann, Juliette Brandes-Schramm, Petra Funk, Heinrich Matthys, and Wolfgang Kamin. “Effects of Pelargonium Sidoides Extract EPs 7630 on Acute Cough and Quality of Life – a Meta-Analysis of Randomized, Placebo-Controlled Trials”. Multidisciplinary Respiratory Medicine 17 (August 3, 2022). Accessed July 7, 2024. https://mrmjournal.org/index.php/mrm/article/view/868.