One of the best and most effective ways to conduct a literature review is to put the literature to work for you- once you have found an article that is perfectly on your topic (or is closely related, or cover's one aspect) you have in your hands the key to finding many more articles. How? By using the references cited in that article to discover more resources on your topic.
Below is a short video about using citations to find other documents:
Once you've found that perfect article, you don't just have to rely on the sources cited in that article- you can search to see if other scholars have cited your perfect article in their work. You can do this by using library databases (Proquest databases in particular often provide "cited by" information on the articles included in their databases), Web of Science, and Google Scholar. See the links below for more information on Web of Science and Google Scholar.
Be sure to check out Web of Science! It is the gold standard for doing this sort of work!
The Web of Science contains several databases:
-Web of Science Core Collection
-Biological Abstracts
-KCI-Korean Journal Database
-MEDLINE
-Preprint Citation Index
-ProQuest Dissertations & Theses Citation Index
-SciELO Citation Index
Searching for studies that use a specific methodology
In the course of your research, you may want to find studies that utilize a particular methodology. Some databases (PsychINFO, for example) allow you to limit to a particular methodology in their Advanced Search options. In other databases, including Proquest social sciences databasese, the best way to find an article using a particular methodology is to add the methodology as a keyword to your search.
The example below is looking for studies about web based instruction that used qualitative research methods 
Proquest Social Science Journals Terms for Research Methodologies
These terms for various methodologies come from the thesaurus in the database.
ERIC Database Terms for Research Methodologies
These terms for various methodologies come from the thesaurus in the database.