- Royal Horticultural Society
- 21 nov 2014
- https://www.rhs.org.uk/plants/search-form
- Royal Horticultural Society
- Journal of Alternative and Complementary Medicine
- 21 nov 2014
- http://www.liebertpub.com/acm
- Mary Ann Liebert, Inc. Publishers
- USDA Nutrient Database
- U.S. Department of Agriculture
- 02 oct 2014
- http://ndb.nal.usda.gov/ndb/search/list
- FAOSTAT
- Food and Agriculture Organization of the United Nations
- 02 oct 2014
- http://faostat3.fao.org/faostat-gateway/go/to/home/E