What are dissertations and how do I find them?

Answer

Dissertations (aka doctoral dissertations) are works of research done as part of the process of earning a PhD.

Theses usually refer to masters-level work done as part of a Master's degree.

Most universities have collections of dissertations written by their own students. Some online universities (usually those without libraries) do not.

Sources for Dissertations:

Some dissertations are made freely available through repositories such as our own IRL@UMSL.
Others, especially older ones, may only be available in print. Sometimes a copy of these can be borrowed via Interlibrary Loan (ILL). However, some must be purchased (ILL will let you know).
Certain dissertations may not be available in any form because the author chose not to release it. They may be planning to expand the dissertation into a book or it may contain proprietary information related to a patent, new product, etc.
Dissertations are listed in the UMSL, University of Missouri Libraries and MOBIUS catalogs as books.

The guide linked below has for more information and possible sources.