Dutch National Archive offers digitized collections, especially colonial archives from Surinam and the West Indies
Research guide to libraries and archives in the Low Countries, by Martha L. Brogan. NY: Greenwood Press, 1991.
LOCATION: Widener: WID-LC Z813.A1 B76 1991
Catalogus Epistularum Neerlandicarum (CEN)
--Records of post-1600 letters in Dutch libraries. Password required.