1. A comparison of the mechanism of action of VP 16 213 and Podophyllotoxin;Horwitz;J Natl Prod,1977
2. The biological effects and the chemical composition of podophyllin. A review;Kelly;J Natl Cancer Inst,1954
3. The chemistry of podophyllin;Hartwell;Fortschr Chem Org Naturst,1958
4. From podophyllotoxin glucoside to etoposide;Stähelin;Prog Drug Res,1989