Doctor of Social Work (DSW) Research: Literature Review Searches

This guide provides links to resources available at USC Libraries for researchers working in the area of social work.

Before Your Search

Search Operators (Boolean Searching)

What are Boolean Operators?

Boolean operators are used by databases to focus searches. Three boolean operators are most recognized by databases: AND, OR, NOT. When using the operators, use them in all CAPS.


  • Use AND to tell the database that your search results must include both or all of your keywords
  • It helps to narrow your results by combining keywords
  • It helps when searching a broad topic, to retrieve fewer results 
  • Example: higher education AND online learning will retrieve results that include are relevant to higher education in relation to online learning


  • Use OR to connect two or more similar concepts

  • It helps to broaden your search and retrieve more results

  • When using this operator, not all results will contain both concepts

  • Example: online learning OR distance education


  • Use NOT to exclude concepts from your search
  • It helps to narrow your search because it excludes concepts
  • It tells the database to ignore results related to a keyword
  • Example: online learning NOT "graduate school" will retrieve results that are relevant to online learning but exclude all results that are related to graduate school


Developing a Search Strategy

Searching Grey Literature

The Cochrane Handbook for Systematic Reviews of Interventions defines grey literature as "the kind of material that is not published in easily accessible journals or databases". 

Search grey literature sources that make the most sense for your research question. These sources can include: materials and research produced by organizations outside of the traditional commercial or academic publishing, conference proceedings, dissertations, published reports or datasets and government documents.

The following sources are recommendations. If you are searching only for grey literature in databases, consider limiting your search by "publication type". Grey Literature can include technical reports, annual reports or government publications, etc. 

General Grey Literature Sources Databases for Grey Literature
Google Scholar Cochrane Library
World Health Organization PsycINFO
Agency for Healthcare Research and Quality Web of Science ProQuest Dissertations