USDA 2002: United States Department of Agriculture, Agricultural Research Service, National Genetic Resources Program. Germplasm Resources Information Network (GRIN) [Online database]. 2002. Ephedra sinica. Beltsville (MD): National Germplasm Resources Laboratory. [Accessed 2009 November 20]. Available from: http://www.ars-grin.gov/cgi-bin/npgs/html/taxon.pl?15236#common