You may find the following tools helpful for beginning, refining, broadening, and accentuating your searches.
Keywords: Choose primary concepts or key words and synonyms germane to the topic you are reseearching. Limit your keyword phrases to no more than 3 words.
Controlled or standardized vocabulary: Preferred words used for searching databases, selected by librarians or other specialists in the field.
Remember: be flexible and prepared to modify your approach when researching a subject. Refine your search terms or repeat searches in different databases for different results.