In fall 1996, the Cotsen staff began compiling a multi-volume book catalogue of the research collection, with support from the Department of Rare Books and Special Collections and the Technical Services Department of the Princeton University Library.00With the publication in 2019 of 'The Nineteenth Century' volumes I (A-K) and II (L-Z), the project now covers publications of the 19th and 20th centuries. These two volumes of the descriptive catalogue include more than 6,370 entries of 19th century illustrated children's books, continuing the series of printed catalogues first published in 2000 and 2003 covering 20th century imprints.00Still planned are a volume covering pre-1801 imprints and an index. When competed, the material will comprise about 20,000 items chiefly in European languages out of a total over 100,000 items published during the fifteenth through twentieth centuries. The entries include detailed notes on illustrations, contents, bindings, and previous owners. As so many children's books appear without dates of publication on their title pages, every attempt has been made to assign an accurate date of issue based on internal evidence and authoritative reference sources in print and on-line. The text is enlivened with more than 270 color-printed illustrations, many full size.0.