1. Negri, M., Lotti, G. and Grossman, A. (Eds.) Clinical Perspectives in Endogenous Opioid Peptides, Wiley, Chichester, 1992.
2. Kallick, D.A., J. Am. Chem. Soc., 115 (1993) 9317.
3. Kallick, D.A., Tessmer, M.R., Watts, C.R. and Li, C.-Y., J. Magn. Reson. Ser. B, (1995) in press.
4. Benham, B.A. and Deber, C.M., J. Biol. Chem., 259 (1984) 14935.
5. Deber, C.M. and Benham, B.A., Proc. Natl. Acad. Sci. USA, 81 (1984) 61.