1. Antibiotics in acute bronchitis: a meta-analysis;Bent;Am. J. Med.,1999
2. Efficacy of extract of Pelargonium sidoides in children with acute non-group A beta-hemolytic streptococcus tonsillopharyngitis: a randomized, double-blind, placebo-controlled trial;Bereznoy;Altern. Ther. Health Med.,2003
3. Umckaloabo im Vergleich zu Acetylcystein bei Kindern mit akuter Bronchitis: prospektive, randomisierte, kontrollierte, offene Studie zur Wirksamkeit und Verträglichkeit;Blochin;Der Kassenarzt.,1999
4. Treatment of acute bronchitis in adults with a Pelargonium sidoides preparation (EPs®7630): a randomized, double-blind, placebo-controlled trial;Chuchalin;Explore (NY),2005
5. Extract of Pelargonium sidoides (EPs®7630) inhibits the interactions of Group A – streptococci and host epithelia in vitro;Conrad;Phytomedicine,2007