Zanker, JM Max Planck Institute for Biological Cybernetics, Max Planck Society; Former Department Structure and Function of Natural Nerve-Net , Max Planck Institute for Biological Cybernetics, Max Planck Society;
https://www.sciencedirect.com/science/article/pii/004269899390258X (Publisher version)
Zanker, J. (1993). Theta motion: a paradoxical stimulus to explore higher order motion extraction. Vision Research, 33(4), 553-569. doi:10.1016/0042-6989(93)90258-X.