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.
In this 1878 private letter to the Rev. W. Diemer (cf. 1881.07), Kuyper declares that he desires with all his heart to reunite the Dutch Reformed Church with the other Reformed churches. Diemer published this private correspondence in 1882 to indicate that Kuyper was now sounding a completely different tune. Kuyper responded with 1882.03.