Brouillet, L., F. Coursol, S.J. Meades, M. Favreau, M. Anions, P. Bélisle & P. Desmet. 2010+. VASCAN, the Database of Vascular Plants of Canada. http://data.canadensys.net/vascan/ (consulted on 2018-01-12)
usda.gov
plants.usda.gov
USDA, NRCS. 2018. The PLANTS Database (http://plants.usda.gov, 12 January 2018). National Plant Data Team, Greensboro, NC 27401 – 4901 USA.
worldcat.org
1929-, Duke, James A. Handbook of medicinal herbs. 2nd. Boca Raton, FL, CRC Press, 2002. ISBN 0849312841. OCLC 48876592.