a long essay or dissertation involving personal research, written by a candidate for a college degree
a lengthy, formal written treatise or thesis, especially an account of scholarly investigation or original research on a specialized topic, submitted to a university in partial fulfillment of the requirements for a Ph.D. degree
Theses are specialized and may only be useful if you are doing in-depth research, such as for an honors thesis or independent study, or the topic is very new and not much has been published on it.
Factors to consider:
Indication for a thesis is often buried in the reference.
Martin, A. P. (2009). Mt. Morning, Antarctica; geochemistry, geochronology, petrology, volcanology, and oxygen fugacity of the rifted Antarctic lithosphere. 413 p.
Degree Granting Institution: University of Otago: Dunedin, New Zealand; Doctoral
Cole, S. J. (2015). Essays on Unconventional Monetary Policies.
Publisher Information: University of California, Irvine
Publication Type: Dissertation
International Bibliography of Art
Roussinova, Roussina. The Art of Pleasing the Eye : Portraits by Nicolas De Largillierre and Spectatorship with Taste for Colour in the Early Eighteenth Century. 2015.
Publisher: Department of Culture and Aesthetics; Stockholm University
Document type: Dissertation Or Thesis
Ivins-Hulley, Laura. Cinema As Surrealist Tool: The Films Of Jan Svankmajer. 350 p.
Indiana U, 2015
Publication Type: dissertation abstract
Daye, E. C. (2016). Correlations between childhood obesity and obesogenic environmental variables within Durham county, North Carolina.
Document Type: Dissertation [no indication of institution]
Compilations of theses:
Usually dissertations are available only at the degree-granting institution. Some institutions post dissertations freely online through their digital repository (linked through the library).
You may be able to find the dissertation published as the author's first book (often with a similar title) or selected chapters published as articles.