derivative work of the following images: File:Mona_Lisa,_by_Leonardo_da_Vinci,_from_C2RMF_retouched.jpg licensed with PD-Art, PD-retouched-user 2011-08-18T17:33:23Z
modified picture. The origin file can be found as follows https://commons.wikimedia.org/wiki/File:Mona_Lisa,_by_Leonardo_da_Vinci,_from_C2RMF_retouched.jpg