Inst. Math. Appl. 12:207-214. Zeeman, E.C. (1977) Catastrophy Theory, Selected Papers, 1972-1977. Addison- Wesley, Reading. MA Zeman, P., Toth, G., Kvetnanasky, R. (1987) Thermodynamic analysis of rat brain opioid mu-receptor-ligand interaction. Gen. Physiol. Biophys. 6:237-248 Zimmerman, |.D., Rapp, P.E. (