Select the most important 2-3 ideas related to your topic. Put the word AND between each new word or idea; this tells the database to look for resources with ALL your terms.
Ebola AND epidemiology
Use quotation marks ( " " ) around phrases (two or more words); this tells the database to look for the words in a specific way.
"Human papillomavirus" AND vaccine
Use the asterisk (*) to truncate a word; this tells the database to look for all words that have the same base. In the example below, search results would include diagnose, diagnoses, diagnosed, etc.
"Candida albicans" AND diagnos*