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 letter Kuyper informs the directors of the Dutch Workingmen’s Union “Patrimonium” that he gratefully accepts its offer of honorary membership. The honorary membership had been offered for his journalistic work relating to the social question and for his leadership at the Vrije Universiteit, which “must be regarded as the crown and ornament of the struggle for free Christian education.”
The Dutch Workingmen’s Union “Patrimonium” was the first Christian social organization in the Netherlands (established in 1877). It was not a labor union but a union of laborers with general social and cultural purposes. Klaas Kater (1833–1916), one of the founders, was Patrimonium’s first chairman (1877–1900).