Burdock

A. A. Silver, and John C. Krantz jr, "The Effect of the Ingestion of Burdock Root on Normal and Diabetic Individuals A Preliminary Report", Annals of Internal Medicine 5(3), (1931), 274-284

Chen, Fu-An, An-Bang Wu, and Chau-Yang Chen, "The influence of different treatments on the free radical scavenging activity of burdock and variations of its active components", Food Chemistry 86(4), (2004), 479-484

Lin, Chun-Ching, Jer-Min Lin, Jeng-Jer Yang, Shu-Chuan Chuang, and Takashi Ujiie, "Anti-inflammatory and radical scavenge effects of Arctium lappa", The American Journal of Chinese Medicine 24(02), (1996), 127-137

Nettle

P. Mittman, “Randomized, double-blind study of freeze-dried Urtica dioca in the treatment of allergic rhinitis”, Planta Med 56(1), (1990), 44-47

Quercetin

A. Crozier, B. Daneshvar, L. O. Dragsted, J. Haraldsdottir, P. Knuthsen,  S.T.  Lauridsen, S. E. Nielsen, B. Sandstrom and J. F. Young, “Effect of fruit juice intake on urinary quercetin excretion and biomarkers of antioxidative status”, Am J Clin Nutr 69(1), (1999), 87-94

B. Stavric, “Quercetin in our diet: from potent mutagen to probable anticarcinogen”, Clin Biochem 27(4), (1994), 245-248

W. J. Angerson, M. E. Lean, and M .Noroozi, “Effects of flavonoids and vitamin C on oxidative DNA damage to human lymphocytes”, Am J Clin Nutr  67(6), (1998), 1210-1218