Zhao, Xinjie, et al. “Composition of Flavan-3-Ol Monomers in Mature Cabernet Sauvignon Fruit at Different Grapevine Age in Yantai, China”. Asian Journal of Chemistry, vol. 25, no. 6, Jan. 2013, pp. 3127-33, doi:10.14233/ajchem.2013.13551.