A.S. Luchins & E.H. Luchins: Comments on the Concept of Closure: Gestalt Archive: Comments on the Concept of Closure by Abraham S. Luchins and Edith H. Luchins
In Search of the Laws of Visual Grouping: From Michael Kubovy Perception Lab
On Perceptual Grouping: Adapted from Max Wertheimer, Untersuchungen zur Lehre von der Gestalt, II. Psychologische Forschung, 1923, 4,301-305. By Charles F. Schmidt
Rudolf Arnheim: Entropy and Art (1971): An Essay on Gestalt psychological views on disorder and order.