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.