The GeoRef database indexes several thousand journals in 40 languages as well as books, maps, reports, most U.S. Geological Survey publications, and American and Canadian masters and doctoral theses.
Boolean Operators
| Boolean operator | Example |
| OR | constructed OR artificial |
| AND | (constructed OR artificial) AND wetlands |
| NOT | greenhouse NOT "greenhouse effect" |
Proximity Operators
Use proximity operators to find phrases and words in close proximity to one another. Quotation marks can be used to retrieve words in a specific order. THe NEAR operator will retrieve words in any order. You can specify the number of words in between your terms by adding a forward slash and number. For example, NEAR/2 will retrieve terms within two words of each other.
| Proximity operator | Example |
| " " | "green roof" |
| NEAR | runoff NEAR/2 water |
Publications indexed in GeoRef are assigned one more controlled vocabulary terms from the Geosciences Thesaurus. Below are a few examples of water-related controlled vocabulary terms. You can use these terns in your initial search or to filter your keyword search results. Use the Thesaurus search option to explore more terms.