Nederlands Fotomuseum
http://www.nederlandsfotomuseum.nl/

Dutch photographers from 1839
http://www.fotografen.nl/

Collection De Waarheid at the International Institute of Social History
http://www.iisg.nl/archives/en/files/w/10776615.php

Collection Algemeen Hollands Persbureau at the International Institute of Social History
http://www.iisg.nl/collections/ahf/

Website of photographer Kors van Bennekom, employed by De Waarheid from 1956 to 1965
http://www.korsvanbennekom.com/