The following web sites and library database may help you to identify terms and phrases related to your topic.
Once you have identified a topic, select the terms and phrases that are essential to understanding the topic.
For example:
Topic – Due to its "abstinence only" sex education policy in Africa, the United States has an obligation to African children whose parents have contracted AIDS since this policy's enforcement.
Keywords: AIDS, Africa, children, sex education, US policy
Once you have identified the keywords, use a concept map to brainstorm related terms and phrases. If you are having trouble identifying additional keywords, thesauri, dictionaries, encyclopedias, and online encyclopedias like Wikipedia can be great places look for inspiration.