Your best friend in searching can be the asterisk (*). Why? Because it can be substituted for any number of letters that follow the "root" word you type.
For example, you can search for environment* and find any word that starts with environment. That means you'll get environment, environmental, environmentalism, environments, and any other possible words using your "root."
To be a sophisticated, successful searcher, you can combine AND with OR in OneSearch with one more fancy trick--using parentheses (). Think of a set of parentheses as a "corral" for your search results. Any time you create a search, your results need to be controlled in a fenced-in area (the parentheses). Here's an example using some of the terms from the list above:
(environment* OR sustainab* OR green OR greening) AND (business OR manage* OR corporation OR organization)