* This Dynamic Planet (US Geological Survey Map I-2800, 3rd edition)
* Cosmic Earth Impacts History Page (Lunar and Planetary Institute)
* Holocene_Impact_Working_Group (http://en.wikipedia.org/wiki/)
* Terrestrial Impact Crater Slide Set (Lunar and Planetary Institute)
* Chicxulub and the Gulf of Mexico (Miami University of Ohio)
* Impact Field Studies Group (http://eps.utk.edu/ifsg.htm)
* Earth-Meteor Impact Crater Maps (geology.com)
* The Chicxulub Debate (Princeton University)
* MantlePlumes.org (http://mantlepumes.org/)