"Echinacea for prevention of the common cold: an illustrative overview of how information from different systematic reviews is summarised on the internet" (2009). Preventive Medicine49 (2–3): 78–82. doi:10.1016/j.ypmed.2009.04.006. PMID 19389422.
"Echinacea for prevention of the common cold: an illustrative overview of how information from different systematic reviews is summarised on the internet" (2009). Preventive Medicine49 (2–3): 78–82. doi:10.1016/j.ypmed.2009.04.006. PMID 19389422.