Google Scholar searches specifically for scholarly materials, including Open Access (freely available) dissertations and theses. Many institutions make their dissertations publicly available, making Google Scholar a great place to search.
See the Library's guide on Google for Academic Research for more information.
If the Library does not have a copy of a dissertation or a theses, use ProQuest Dissertations and Theses to obtain a citation for the dissertation. Most American and Canadian universities are represented in this database, as well as selected British and European universities. Dissertations completed at many major U.S. universities during the past 10 years (and sometimes earlier) are available as full-text downloads.
If full text is not available, you can request a dissertation through interlibrary loan.
A note on terminology for dissertations and theses: these words are used differently depending on the country (at least in the English speaking world). In the US, dissertations are for doctoral work while a thesis can be a for a bachelor’s or master’s degree. However, it’s often flipped in Europe, e.g., a master’s dissertation and a doctoral thesis.