UIUC Online Catalog - Searches all UIUC libraries.
You can use subject headings to refine your search. So if, for instance, you are looking for specific ethnic and racial history or statistics of the city of Chicago, you can use these headings:
Chicago (Ill.)—Ethnic relations
Just copy and paste one of the above headings into the search field, and select "Subject" as the category.
If a book is not available at UIUC . . .