If a dissertation is not available for download, the Interlibrary Loan office can help you in acquiring a copy.
Theses Canada Portal provides a searchable catalog of all Canadian thesis published since 1965, many of which are available in full text electronic versions which can be downloaded free by students, scholars, and the public.
A collection of over 200,000 theses and dissertations from around the world. Many items, including those dating back to the early 1900s, are available in full text for free. For those not available in full text, fill out a standard interlibrary loan request.
The UIUC Library should have at least one copy of all theses and dissertations granted at UIUC. The UIUC Library may also have selected theses and dissertations from other institutions, so the online catalog is a good place to look first. Copies of dissertations deposited at UIUC from 1978 to the present are accessible by author and title through the I-Share Catalog. Beginning with 1983, archival copies can also be searched by department and year.
If you quickly need a print copy of a dissertation that is not available for download and don't mind paying the full cost yourself, you can order it directly from Proquest's Dissertation Express as an individual. Otherwise, use one of the Interlibrary loan options described above.