American Numismatic Association http://www.money.org
American Numismatic Society http://numismatics.org/
Bureau of Engraving and Printing http://www.bep.gov
C4 http:// www.colonialcoins.org
Early American Coppers http://www.eacs.org
Garden State Numismatic Association http://www.GSNA.org
Newman Numismatic Portal http://www.nnp.wustl.edu
Medal Collectors of America http://www.medalcollectors.org
Society of Paper Money Collectors http://www.spmc.org
US Mint http://www.usmint.gov