Request a dissertation via Interlibrary Loan, or Tipasa. Tipasa is a service that will provide you with materials that LVC does not own.
WorldCat Dissertations will provide a Request from LVC Tipasa link on each of the results you find.
You can also request a dissertation from the Interlibrary Loan link on the library's homepage. Note that not all dissertations will be available to borrow.
If we can borrow them, you'll either get a PDF of the dissertation sent to you electronically, or a hard copy that will need to be returned.
A dissertation is required of doctoral study; it is a lengthy, formal document that presents new research, and that argues in defense of a particular
thesis.
Dissertations can be useful for in-depth research.
Image source: Google Books. 1837. Public domain.