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- When using Discover@UMSL, you should avoid typing full questions—such as “What are the best ways to reduce plastic waste?”—and instead only type a few key words—such as plastic waste reduction methods.
- Since we’re looking specifically for articles about plastic waste and not articles about waste where the word plastic is only mentioned in passing, we can search for the exact phrase by enclosing it in double quotation marks—“plastic waste” reduction methods. Be careful though: doing this will eliminate any articles that use the term plastics waste.
- Discover@UMSL and most library databases combine words and phrases with the Boolean operators AND, OR, and NOT. As you can see from the diagram below, AND will reduce the number of results and OR will expand the number of results.

- AND is the default operator, so “plastic waste” reduction methods is actually seen by the search engine as “plastic waste” AND reduction AND methods. Each term you add reduces your results. This is why you don’t want to use more words than absolutely necessary!