Kerzel, D., H. Hecht, and N. G. Kim, "Time-to-passage judgments on circular trajectories are based on relative optical acceleration", Perception and Psychophysics, vol. 63, pp. 1153-1170, 2001.

Kerzel, D., and H. Hecht, "Interdisciplinary perspectives on causation", Visual causality, vol. 4: G. Grabhoff, T. Lampet & T. Sauer, pp. 119-139, 2001.