If you search a catalog or database and receive a large number of results, add a limit or additional keyword in order to retrieve a manageable and relevant number of results to review. At the same time overly narrow search terms can return too few results. One way of solving both problems is to use Boolean operators (AND, OR, NOT). They allow you to define concepts and determine their relationships. They also give you opportunities to limit or expand searches depending on your needs.
A search for migrant AND protection will return items that contain both terms:
immigrant OR refugee allows you to put related words together with results that contain either one of the terms or both:
human rights NOT trafficking returns items that talk about humans rights issues but do not mention trafficking:
Phrase searching:
An important strategy to use when searching for phrases or titles:
"human rights"
will search for those words in that order
Truncation and Wildcards:
Most catalogs and databases enable users to search variations of keywords by using truncation (*) or wildcard (e.g., ?, $, !) symbols.
For example, one could search for politic* to find poltic, politics, political, politicking, and so on.
Wildcard searches are for differences within words: a search for wom?n will return results for woman, women, and womyn.
Nested Searching:
When pairing two or more keywords and connecting them to other concepts, it is important to "nest" the former terms within a larger Boolean search. (immigrant* OR refugee*) AND ("human rights")
Focus Your Search:
Choose where the database is searching. It may be set automatically for keyword. You can make the search more precise by looking instead for words in subjects or abstracts.
Putting Your Search Statement Together:
("social movement* OR protest OR protests) [as Subjects] AND (poverty OR poor) [as Subjects] AND "united states" [as Subject] 
In Proquest Research Library this search returns 135 articles including:
"Something to Help Themselves: Tenant Organizing in San Francisco's Public Housing, 1965-1975"
Baranski, John Journal of Urban History 33, 3 (2007): 418-442