1. Schmidt, U., A. Lieberknecht, and E. Haslinger Peptide Alkaloids in “The Alkaloids”. A. Brossi (Ed.), Academic Press, New York, Vol. 26, p. 299 (1985).
2. Tschesche, R., and E.U. Kaussmann: The Cyclopeptide Alkaloids in “The Alkaloids”. R.H.F. Manske (Ed.), Academic Press, New York, Vol. 15, Chapter 4, p. 165 (1975).
3. Tschesche, R.: Cyclopeptide Alkaloids Containing a Styrylamine Ring Unit. Hetero-cycles, 4, 107 (1976).
4. Shah, A.H., and V.B. Pandey: Progress in the Chemistry of Cyclopeptide Alkaloids Containing a Styrylamine Unit. J. Chem. Soc. Pak., 7, 363 (1985).
5. Bhat, K.L., and M.M. Joullié: Cyclopeptide Alkaloids. J. Chem. Educ, 64, 21 (1987).