A revised and updated version of
Abraham Kuyper: An Annotated Bibliography 1857-2010 by Tjitze Kuipers (2011)
You can buy a printed edition of this book on the site of the publisher.
1980
Volume 175 of the large series of the Rijks Geschiedkundige Publicatiën (RGP) [State Historical Publications] contains thirty-five letters exchanged between Kuyper and Groen van Prinsterer during the period October 6, 1864–May 30, 1869. Eighteen of the letters (October 6, 1864–May 11, 1869) were written by Kuyper. Kuyper began the correspondence with a request that Groen van Prinsterer use his influence to secure permission for Kuyper to copy a handwritten work by A. Lasco in the Königliches Geheime Archiv [Royal Secret Archive] at Königsberg, Prussia. The first four letters have to do with that request. The subsequent letters concern the establishment of the Marnix Society (see 1868.11) and, as the correspondents begin sending each other copies of their recent publications, gradually broaden to include topics such as the church, Christian education, politics, and private affairs.