Bibliografía (4 obras)
The Official American Numismatic Association Grading Standards for United States Coins (Official American Numismatic Association Grading Standards for United States Coins)
1997
AMERICAN JOURNAL OF NUMISMATICS 1 Second Series The American Numismatic Society Museum Notes
1989
The official American Numismatic Association grading standards for United States coins
1977
A catalogue of convention badges & medals, 1908-1968
1969
