In Libsearch you find journal articles, books, theses and more. It is an alternative to Google Scholar, and almost all content from the Library's databases are drawn together in one index.
LLBA covers research in linguistics and related disciplines in the language sciences. The place to start when studying linguistics.
MLA International Bibliography contains articles, books and research on literature, language and linguistics from 1923 to present.
The articels in Project MUSE covers the fields of literature and criticism, history, the visual and performing arts, cultural studies, education, gender studies and many others. The fulltext coverage vary, but are often from year 2000 and onwards.
More databases that could be relevant to you depending on your thesis topic:
News articles (no research literature) from key international sources on world economics, politics, sports, cultural activities. Special reports focus on topics of current interest. Coverage: 2004 – current
Google Scholar enables you to search specifically for scholarly literature, including peer-reviewed papers, theses, books, preprints, abstracts and technical reports from all broad areas of research.
Sociological abstracts contains references to research publications (journals, books and conferences) in sociology and related disciplines in the social and behavioral sciences.