Web sites:

USDA-NCGR, Corvallis, OR: http://www.ars.usda.gov/Main/docs.htm?docid=11353

Ribes Diagnostic Tool: http://www.ars-grin.gov/cor/ribes/ribsymp/ribsymp.html

Commercial sources cultivars- http://www.fruit.cornell.edu/Berries/nurseries/index.html

UK New Crops Center http://www.uky.edu/Ag/NewCrops/introsheets/currants.pdf