Betulinic Acid, a Catalytic Inhibitor of Topoisomerase I, Inhibits Reactive Oxygen Species–Mediated Apoptotic Topoisomerase I–DNA Cleavable Complex Formation in Prostate Cancer Cells but Does Not Affect the Process of Cell DeathAgneyo Ganguly, Hemanta K. Majumder, Sibabrata Mukhopadhayay et al.|Cancer Research|2007Cited by 91