M. L. Braunstein and G. J. Andersen,“A counterexample to the rigidity assumption in the visual perception of structure from motion,” Perception, vol.13, pp. 213-217, 1984.
J. E. Cutting, C. Moor, and R. Morrison,“Masking the motion of human gait,” Percept. Psychophys., vol.44, pp. 339-347, 1988.