1. What's up with herbals?;Bokma;Pharm Pract,2000
2. Trends in alternative medicine use in the United States, 1990-1997;Eisenberg;JAMA,1998
3. Decima Research Inc. Public Opinion Survey on Key Issues Pertaining to Post-market Surveillance of Marketed Health Products in Canada: Final Report. 2003.
4. Health Canada. Natural health products. Available at: http://www.hc-sc.gc.ca/dhp-mps/prodnatur/index_e.html. Accessed 24.03.06.