Learn background information and synonyms from reference sources. This is when Wikipedia is helpful, although you should also try the database Credo General Reference and the books listed below.
Create a list of synonyms. For example, try internment as well as "concentration camps" and also specific examples i.e. Auschwitz and Dachau.
Use quotation marks around phrases, i.e. "consumer behavior" or "acid rain."
Find multiple word endings. This is the asterisk in most library databases. For example child* will find child, childish, children, child's, etc.
Use "united states" not "america" or "USA."
Reviews are NOT helpful articles, unless you want to read someone's opinion about a book or movie they read or watched. Look at "types of articles" in the left column and use the check boxes to select the types of articles you want to include in the list of results. And then you still need to watch for the word "review" as a subject heading.