HPLC method for the quantification of procyanidins in cocoa and chocolate samples and correlation to total antioxidant capacity,
Adamson, G. E., Lazarus S. A., Mitchell A. E., Ronald L., Cao G., Jacobs P. H., Kremers B. G., Hammerstone J. F., Rucker R. B., and Ritter K. A.
, Journal of Agricultural and Food Chemistry, 1999, Volume 47, Issue 10, p.4184 - 4188, (1999)