References:
1.Chuchalin AG, Berman B, Lehmacher W. Treatment of acute bronchitis in adults with a Pelargonium sidoides preparation (EPs 7630): a randomized, double-blind, placebo-controlled trial. Explore (NY). 2005 Nov;1(6):437-445. http://www.ncbi.nlm.nih.gov/pubmed/16781588
2.Matthys H, Kamin W, Funk P, Heger M. Pelargonium sidoides preparation (EPs 7630) in the treatment of acute bronchitis in adults and children. Phytomedicine. 2003;14 Suppl 6:69-73. http://www.ncbi.nlm.nih.gov/pubmed/17184981
3.Matthys H, Heger M. Treatment of acute bronchitis with a liquid herbal drug preparation from Pelargonium sidoides (EPs 7630): a randomised, double-blind, placebo-controlled, multicentre study. Curr Med Res Opin . 2007;23:323-331.http://www.ncbi.nlm.nih.gov/pubmed/17288687