S. G. Lucas and R. M. Sullivan. 2006. Tetrapod footprints from the Upper Triassic Passaic Formation near Graterford, Montgomery County, Pennsylvania. In J. D. Harris, S. G. Lucas, J. A. Spielmann, M. G. Lockley, A. R. C. Milner, & J. I. Kirkland (eds.), The Triassic-Jurassic Terrestrial Transition. New Mexico Museum of Natural History and Science Bulletin 37:251-256 [M. Carrano/M. Carrano]