When searching in the databases for articles the following tips may help you:
* - This is the truncation symbol. It searches for variations of your term. For example: biolog* will return: biology, biological, biologist, biologist.
AND - Use the word AND when you want to combine search terms (this will reduce the number of items found). For example: smoking AND prevention will find articles that discuss BOTH smoking and prevention.
OR - Use the word OR when you are searching for a topic that may have different names (this will expand the number of items found). For example: brain OR neurologic will find articles with either one of these words.
NOT - Use the word NOT when you want to exclude certain terms from your results. For example: wolf NOT spider will find articles that talk about the wolf but exclude any that are about the wolf spider.