WIKIPEDIA
| Date | Clue |
|---|---|
| 2022-02-28 | Popular online reference |
| 2022-02-25 | Much-visited website run by a nonprofit foundation |
| 2020-10-23 | Resource with content in 300+ languages |
| 2017-11-02 | Many teachers disallow it in footnotes |
| 2010-02-01 | Popular online reference |
| 2009-04-18 | Its symbol is a globe composed of jigsaw puzzle pieces |
| 2007-07-20 | Popular reference work |