(en) Woelk, H. & Schläfke, S. (2010). A multi-center, double-blind, randomised study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder. Phytomedicine17(2): 94–9. DOI:10.1016/j.phymed.2009.10.006. PMID19962288.
(en) Woelk, H. & Schläfke, S. (2010). A multi-center, double-blind, randomised study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder. Phytomedicine17(2): 94–9. DOI:10.1016/j.phymed.2009.10.006. PMID19962288.