The Digital Library of the Catholic Reformation makes the documentary riches of this era accessible, adding functionalities that maximize the flexibility with which researchers can search, view, organize, and manipulate this historically important source material. With new content uploads occurring on a regular basis, the database offers a constantly growing treasury of documents, including papal and synodal decrees, catechisms and inquisitorial manuals, biblical commentaries, theological treatises and systems, liturgical writings, saints' lives, and devotional works.

This catalogue records information in e-journals, e-books, databases, and printed material about themes in the field of the international law. Especially, a large part of the print collection of the Peace Palace Library is searchable through this catalogue. This collection consists of books and materials since 1913.

The Digital Library of Classic Protestant Texts gives researchers access to an extensive range of seminal works from the Reformation and post-Reformation eras. With new content uploads occurring on a regular basis, the database offers a constantly growing treasury of theological writings, biblical commentaries, confessional documents, and polemical treatises written by more than 300 Protestant authors.