Canada and U.S.
If a Canadian or U.S. thesis is not available online you may request it via Interlibrary Loans.
Universities hold copies of most of the theses done at their own institution. As well, Library and Archives Canada holds one copy of every thesis completed at a Canadian University.
You can order theses and dissertations from other countries via Interlibrary Loans. To do so, fill out the blank order form in RACER with the details of the thesis: author's name, title, year, name of degree-granting institution, etc.
Note: process can take a long time (3 months +) and may not be free.