debate or controversy (or controvers* to pick up variants), or contested or disputedoften help you surface works that identify the "stakes" of a particular argument, action, phenomenon, etc. So will words like proponents, advocates or their opposites: opponents or critics.
theoryortheoreticalor philosophyor philosophical might help you find works in larger contexts or examined via a "lens" of some kind.
handbookorcompanionor encyclopedia are common words to help identify good background or overview sources.
criticism or interpretationare words that will bring up secondary source studies of a book, film, artwork, musical piece, play, artist or writer, etc.
history is a way to get at full-length studies not just of countries or events, but also of ideas and concepts and broad subjects.
Specifically for Studio 20 projects that are looking at barriers to something: try adding that word -- or its opposite, access.
For Primary Sources
narrative*or case study or interview* or memoir or even the phrase "lived experiences" might angle topics more specifically toward studies of social relationships, observations of behavior, personal reflections, explanations or first hand "testimony" of some kind.
qualitative is one way social science researchers describe their non-numeric data collection methods -- and "qualitative" generally means interviews, focus groups, observed behavior of some kind.
Anthropologists sometimes call their observational methods ethnography, so you might try that word (or ethnograph*) as well.
interview is also a great word to use in newspaper searching, when you're looking for primary evidence in the form of personal stories or first-hand accounts and testimonies.
While a biographyis technically a secondary source (a second-hand account of a life), biographies are built out of a whole host of primary sources: documents, papers, interviews, correspondence, etc. So you might find your primary sources, sometimes, by "reverse engineering" from a secondary source.
