Alcock, J. (1993). Animal behavior: An evolutionary approach (5th ed.). Sunderland, MA: Sinauer Associates.

Braitenberg, V. (1984). Vehicles: Experiments in synthetic psychology. Cambridge, MA: MIT Press.

Burghardt, G. M. (1970). Defining ``communication''. In J. W. Johnston Jr., D. G. Moulton, & A. Turk (Eds.), Communication by chemical signals. New York: Appleton-Century-Crofts.

Hand, C. (1994). Object oriented logic (Tech. Rep. No. CS-94-235). Knoxville, TN: Computer Science Department, University of Tennessee.

Lindauer, M. (1961). Communication among social bees. Cambridge, MA: Havard University Press.

MacLennan, B. J. (1990). Evolution of communication in a population of simple machines (Tech. Rep. No. CS-90-99). Knoxville, TN: Computer Science Department, University of Tennessee.

MacLennan, B. J. (1992). Synthetic ethology: An approach to the study of communication. In C. G. Langton, C. Taylor, J. D. Farmer, & S. Rasmussen (Eds.), Artificial life II. Redwood City: Addison-Wesley.

MacLennan, B. J. & Burghardt, G. M. (1993). Synthetic ethology and the evolution of cooperative communication. Adaptive behavior, 2, 161-188.

Morton, E. S., & Page, J. (1992). Animal talk: Science and the voices of nature. New York: Random House.

Sebeok, T. A. (Ed.). (1968). Animal communication: Techniques of study and results of research. Bloomington: Indiana University Press.

Werner, G. M. & Dyer, M. G. (1992). Evolution of communication in artificial organisms. In C. G. Langton, C. Taylor, J. D. Farmer, & S. Rasmussen (Eds.), Artificial life II. Redwood City: Addison-Wesley.