Gibson, J. J. On the concept of "formless invariants" in visual perception. Leonardo, 1973, 6, 43-45., 1973

Gibson, J. J. On the concept of "formless invariants" in visual perception. Leonardo, 1973, 6, 43-45., 1973, Box: 10, Folder: 28. James J. Gibson papers, 14-23-1832. Division of Rare and Manuscript Collections. https://archives.library.cornell.edu/repositories/2/archival_objects/820239 Accessed January 18, 2026.