Before you start searching for books, articles or web pages, you need to choose keywords that represent your research topic.
Keywords are significant words (usually nouns or noun phrases) which can be used as search terms in online catalogs or databases. They can appear in the title, subject headings, abstract, or text of records. A keyword search typically searches all or most of these fields.
Here is an example of a narrow keyword with synonyms:
Civil War Diet
"American civil war"