Revision history for entry Penrose, Lionel S.; Penrose, Roger (1958). "Impossible objects: A special type of visual illusion" [PENIOA]

NB: for privacy reasons, few details are provided in public revision histories.
TimeTypeNotes
2015-01-20T20:59:45update
2013-10-29T19:55:08updateSystem / admin update -
2009-09-10T12:56:06addSystem / admin update -