Databases specializing in communication can be combined with those in other fields in one search.
Start with an EBSCO database like Communication and Mass Media Complete.
On the screen that appears, you can check mulitple databases.
For an communication theory literature review, I might add general databases like Academic Search Premier, ERIC (for an education topic), Business Source Premier (for a marketing topic), PsychArticles (for psychology), or ATLA (for religion).
When doing a literature review on a topic. Frequently "studies" and/or "research" are the preferred type of article. In all the databases, you can limit to scholarly or "peer reviewed" and that helps.
Adding the word "methodology," "research," or "study" to your key word search can increase the usefulness of your search results.
(Example: "cultivation theory" and methodology)
Remember "research articles" frequently contain the following information (usually denoted by separate headings).
ABSTRACT * RESEARCH * METHODOLOGY * CONCLUSIONS * REFERENCES
Search Google Scholar to find citations to scholarly articles.
While some articles are freely available via the web, many are not. If you find a useful article citation using Google Scholar, check the Berntsen Library's Journal Title Search to see if you can access the journal via the library. Otherwise, you may request the article via Inter-Library Loan by submitting a request through ILLiad.