There are several places where you can search for the texts that you will need for your review:
Other useful sources include the bibliographies of similar research, course readings (this is especially useful for locating key works), or journals that specialize in overviews of a research field, e.g. Progress in Human Geography or Progress in Development Studies.
Note: It is extremely helpful to keep detailed notes on how you conduct your research – this helps you document the research project and helps you avoid duplicating searches.
Where do you find the literature associated with your field of study?