1. Triterpenoids (1997)
2. Birch bark processing and isolation of natural products from birch bark. U.S. Patent 6,392,070; 2002.
3. Method of producing betulinic acid by the fractional extraction of ground plane tree bark using dichloromethane. U.S. Patent 6,175,053; 2002.
4. Betulinic acid derivatives having antiangiogenic activity, processes for producing such derivatives, and their use for treating tumor associated angiogenesis. U.S. Patent 6,403,816; 2002.
5. Preparation of betulinic acid derivatives for pharmaceutical use in the treatment of neuroectodermal tumors. U.S. Patent 6,369,109; 2002.