Most Information searches start with keywords. Keywords allow you to search with natural language, describing a topic in words that you would actually use.
When choosing keywords you should choose words that are most likely to appear in an article of book that would relate to your topic. You should avoid words that are too common and likely to appear in multiple topics.
If you are having trouble choosing keywords, it can help to create a Research Plan:
When you are using a term that is made up of more than one word, it may be necessary to enter the term as a phrase. The most common way of doing this is to surround the term with quotation marks. For example: "fossil fuel." This tells the catalog, database, or search engine that you are only interested in articles where these words appear together and in the correct order. Some databases allow advanced boolean searching which will allow more dynamic ways of searching for phrases.