Gillette, D.D. and M. G. Lockley, editors. 1989. Dinosaur Tracks
       and Traces. Cambridge University Press, Cambridge  England.

Lockley, M.G. and A.P. Hunt.  1995.  Dinosuar Tracks and Other
        Fossil Footprints of the Western United States.  Columbia
        University Press, New York.

Lockley, M. G. 1991. Tracking Dinosaurs. Cambridge University
        Press, Cambridge,  England.

Thulborn, T. 1990. Dinosaur Tracks. Chapman and Hall, London.