Keywords: OR model van Sokolov.png OR model van Sokolov own 2007-08-20 Albert Kok at http //nl wikipedia org nl wikipedia nl wikipedia Albert Kok original upload log page nl wikipedia OR PNG 2007-08-20 15 29 Albert Kok 395×288×8 6771 bytes <nowiki> OR model van Sokolov albert kok publiek domein </nowiki> Psychology Systems psychology |