Book Sales Catalogues Online offers a comprehensive bibliography of book sales catalogues printed in the Dutch Republic before 1801, providing full access to some 4,000 digital facsimiles from ca. 50 libraries across Europe. These catalogues are a key primary source for research on the history of the book and libraries, the history of ideas, the history of collecting, the history of literature, and the history of art. The catalogues contain information on books from all over Europe in various languages, such as Dutch, French, and Latin.

Dutch Pamphlets Online comprises both the complete Knuttel collection from the National Library of the Netherlands and the Van Alphen collection from Groningen University Library. The famous Knuttel collection contains some 34,000 pamphlets, to which the Van Alphen collection adds another 2,800. There is no overlap between the two. Combined, these collections form an exhaustive treasure trove of primary texts on the history of the Low Countries between 1486 and 1853.

In the late 1800's, Dutch physician and feminist Aletta Jacobs and her husband C.V. Gerritsen began collecting books, pamphlets and periodicals reflecting the revolution of a feminist consciousness and the movement for women's rights. By the time their successors finished their work in 1945, the Gerritsen Collection was the greatest single source for the study of women's history in the world, with materials spanning four centuries and 15 languages. The Gerritsen curators gathered more than 4,700 publications from continental Europe, the U.S., the United Kingdom, Canada, and New Zealand, dating from 1543-1945. The anti-feminist case is presented as well as the pro-feminist; many other titles present a purely objective record of the condition of women at a given time.