1. Brown, J. L., Vision and Visual Perception: 479 (1965).
2. THESIS U MICHIGAN 1968
3. Gibson A. paper read at convention of the Eastern Psychological Association (1968).
4. Hajos A. paper read at L Zusammenkunft der Psychologen aus den Donaulindern (1967).
5. Harris C. S. paper read at convention of the Psychonomic Society (1968).