Haynes, William M.; Lide, David R.; Bruno, Thomas J. (2014). "3". CRC Handbook of Chemistry and Physics (95th ed.). Boca Raton, Florida: CRC Press. p. 340. ISBN978-1-4822-0868-9. OCLC908078665.
Green, Brian; Bentley, Michael D.; Chung, Bong Y.; Lynch, Nicholas G.; Jensen, Bruce L. (2007-12-01). "Isolation of Betulin and Rearrangement to Allobetulin. A Biomimetic Natural Product Synthesis". Journal of Chemical Education. 84 (12): 1985. Bibcode:2007JChEd..84.1985G. doi:10.1021/ed084p1985.
Green, Brian; Bentley, Michael D.; Chung, Bong Y.; Lynch, Nicholas G.; Jensen, Bruce L. (2007-12-01). "Isolation of Betulin and Rearrangement to Allobetulin. A Biomimetic Natural Product Synthesis". Journal of Chemical Education. 84 (12): 1985. Bibcode:2007JChEd..84.1985G. doi:10.1021/ed084p1985.
Haynes, William M.; Lide, David R.; Bruno, Thomas J. (2014). "3". CRC Handbook of Chemistry and Physics (95th ed.). Boca Raton, Florida: CRC Press. p. 340. ISBN978-1-4822-0868-9. OCLC908078665.