1. Foxglove tea poisoning;Dickstein, E.S.; Kunkel, F.W.;Am J7 Med,1980
2. Acute, massive poisoning with digitoxin: report of seven cases and discussion of treatment;Hansteen, V.; Jacobson, D.; Knudsen, K.;ClGn Toxicol,1981
3. Carcinogenic activity of symphytum officinsle;Hirono, I.; Mori, H.; Haga, M.;J Natl Cancer Inst,1978
4. Comfrey and liver damage;Roirnan, J.N.;Lancet,1981