Journal of Experimental Biology, 202, 2609-2617, 1999
This paper describes Gibbon Brachiation as a point mass alternately swinging like a simple pendulum or flying like a parabola.
The data collection and reduction was due to Chang and Bertram. The idea for the model was largely mine. The calculations were done equally by me and Cannon. The writing was pretty evenly split between me and Bertram.