Example: "ebola virus"
Enclosing 2 terms in double quotation marks keeps those terms together. This works in most of our databases. However, some search engines require you to put a plus sign before each term you wish to add:
Example: +ebola +virus
This brings only the "hits" to the top of the list that have both terms and increases the relevancy ranking. We will discuss relevancy ranking more when we discuss Google advanced search.