Wertheimer, Max (1912). "Experimentelle Studien über das Sehen von Bewegung" [Experimental studies on the seeing of motion] (PDF). Zeitschrift für Psychologie (en alemany). 61: 161–265. Available in translation as Wertheimer, Max (2012). "Experimental Studies on Seeing Motion". In Spillman, Lothar (ed.). On Perceived Motion and Figural Organization. Michael Wertheimer, K. W. Watkins (trans.).