Standard Catalog of World Coins
The Standard Catalog of World Coins is a series of numismatic catalogues that is commonly known as the Krause catalogues in the numismatic trade. They have been compiled in several volumes for coins that have been issued since 1601 by the team at Krause Publications since the mid-1970's.
The Krause catalogue numbering system uses the references 'KM', 'KMM', 'KMTn.', and 'X'.