1. aKeller, P. A. In Comprehensive Heterocyclic Chemistry III; Katritzky, A. R., Ramsden, C. A., Scriven, E. F. V., Taylor, R. J. K., Eds. Elsevier: Oxford, U.K., 2008; Vol. 7, pp 217–308.
2. b The Alkaloids: Chemistry and Biology; Cordell, G. A., Ed. Academic Press: San Diego, CA, 2000; p 54.
3. c Pharmaceuticals:
Classes, Therapeutic Agents, Areas of Application; McGuire, J. L., Ed. Wiley-VCH: Weinheim, Germany, 2000; pp 1–4.