If you are unfamiliar with a particular database try using the on-line help. Database that don't support full text usually have an abstract. A finite list of words used to index a collection. This is useful in understanding the common terms used by the database. Databases and search engines use Boolean Logic to allow you to narrow or broaden your search.
Most databases allow the use of phrases as search terms.
Phrases are very useful in narrowing a search especially when a phrase is unique to your field of study. Searching Tips Using the most unique words and phrases first. This may include very specific terms or phrases or complete titles. Useful when your original search retrieved too many records. If your search was too specific and returned no or few records reduce the number of keywords or use broader terms.