The online home of CONECA, the Combined Organizations of Numismatic Error Collectors of America.
CONECA's new site devoted to die varieties.
http://coppercoins.com
Website devoted to Lincoln cent varieties
www.minterrornews.com
Mike Byers' website devoted to mint errors. Free download of his quarterly online magazine.
http://traildies.com
BJ Neff's exhaustive study of "wavy steps" and "trails" die varieties.
http://www.numismaticenquirer.com/TNE/Home.html
Information on counterfeit detection.
http://kennedyhalfdollar.com
Site devoted to Kennedy halves, including errors and varieties.
http://Error-ref.com
A site devoted to defining errors and varieties.
http://maddieclashes.com/index.html
The site for researching all types of die clashes.