EntityQ3622748· pop 7· linked from 123 articlesEhrenstein illusionSign in to saveoptical illusionConnectionsillusory contourEntityInternational Standard Book NumberEntitydigital object identifierEntityillusionEntityQ180686EntityGestalt psychologyEntitybibcodeEntityoptical illusionEntityQ229883Entityop artEntitycognitive dissonanceEntitytrompe-l'œilEntityWolfgang KöhlerEntityambigramEntityPenrose triangleEntityQ22908627EntityPenrose stairsEntitygravity hillEntityAmes roomEntitymonochromeEntityCategoriesOptical illusions