The UI CIC VEL provides internet access to the catalogs of all Big Ten Universities and the University of Chicago. You may search each catalog individually or all catalogs simultaneously. LCAT is the UI Libraries' online catalog. This database contains records representing all books that have come into the Libraries after 1980-81 . The Oasis system provides UI access to a number of electronic indexes of academic material.
Abstracts are available for some articles.
If you are looking for something published before 1981, then you must check the card catalogs before assuming that the UI does not have it. But that is not the case yet. The card catalog at the Main Library is supposed to contain cards for all items in the University Libraries as they existed before 1981. Many of the listed sets consist of primary historical materials, e.g. manuscript collections, collections of old books, long runs of newspapers. You will need to have a copy of Adobe Acrobat Reader on your computer to read this listing.