Pfeifer and Scheier, "Understanding Intelligence", MIT Press, 2000.

   R. Beer, "Intelligence as Adaptive Behavior.  An Experiment in
   Computational Neuroethology", Academic Press, San Diego, 1990.
   ISBN: 0-12-084730-2

   V. Braitenberg, "Vehicles: Experiments in Synthetic
   Psychology". MIT Press, Cambridge, MA. 1984. ISBN 0-262-02208-7

   Rodney A. Brooks, "A Robust Layered Control System for a Mobile
   Robot", IEEE Journal of Robotics and Automation, 2:14-23, 1986.

   Rodney A. Brooks, "A Robot that Walks: Emergent Behaviour from a
   Carefully Evolved Network", Neural Computation, 1(2), 1989.

   W. Lim and J. Eilbert, "Plan-behaviour interaction in autonomous
   navigation", Proceedings of the SPIE, 1388:464-475, 1991.

   Pattie Maes and Rodney A. Brooks, "Learning to Coordinate Behaviours", 
   Proceedings of AAAI-90, 1990.

   Pattie Maes, "Designing Autonomous Agents: Theory and Practice from
   Biology to Engineering and Back", MIT Press, 1991.

   T. Tyrrell, "The Use of Hierarchies for Action Selection", From
   animals to animats2:  Proceedings of the Second International
   Conference on Simulation of Adaptive Behavior, 1993.
   
   T. Tyrrell, "Computational Mechanism for Action Selection", PhD
   Thesis University of Edinburgh, 1993.

Animals to Animats Conferences:

   Jean-Arcady Meyer and Stewart W. Wilson, "From Animals to Animats:
   Proceedings of the First International Conference on Simulation of
   Adaptive Behavior (1990, Paris, France)", MIT Press, Cambridge, MA, 1991.
   551 pages, $55, ISBN 0-262-63138-5.

   Jean-Arcady Meyer, Herbert L. Roitblat, and Stewart W. Wilson,
   editors, "From Animals to Animats: Proceedings of the Second
   International Conference on Simulation of Adaptive Behavior", MIT
   Press, Cambridge, MA, 1993. 523 pages, $55, ISBN 0-262-63149-0.

   Francisco J. Varela and Paul Bourgine, editors, "Toward a Practice of
   Autonomous Systems: Proceedings of the First European Conference on
   Artificial Life", Complex Adaptive Systems Series, MIT Press,
   Cambridge, MA, 1992. 515 pages, $55.00, ISBN 0-262-72019-1.