| European Environment Agency | Glossary of the European Environmental Agency |
| Wikipedia | The Free Encyclopedia |
| Encyclopedia Britannica | Highly authoritative source |
| EPA Terms | Glossary of the U.S. Environmental Protection Agency |
| Google Search | The largest Internet Search Engine |
| Google Image | Search for Images related to the term |
| A-Z Biodiversity Terms | Glossary providing definitions of terms, areas and acronyms related to biodiversity, commonly used, internationally recognized where possible, well referenced, and derived from legitimate sources |
