coal ball: References & Edit History
Article Contributors
Primary Contributors
Other Encyclopedia Britannica Contributors
Article History
Type | Description | Contributor | Date |
---|---|---|---|
Changed “the Ukraine” to “Ukraine.” | Mar 09, 2022 | ||
Add new Web site: Emporia State University - Coal Balls: A Key to Ancient Plants. | Mar 16, 2018 | ||
Added new Web site: Department of Environment and Plant Biology at Ohio University - Coal Ball. | Sep 18, 2007 | ||
Article added to new online database. | Jul 20, 1998 |
View Changes:
Article History
Revised:
By: