Literature is an inseparable part of every scientific field, including numismatics. The hobby of collecting coins is not only collecting denominations, years or coins of individual rulers. It is also discovering new varieties, denominations, stamps or developing such branches as heraldry, mint managers, engravers or periods in which individual coins were minted – because not always the year on the coin is the year of mintage
The passion of numismatics is also often associated with numerous statistics – how many coins have appeared in trade (e.g. estimation of the number of very rare variants, in which you have to browse through numerous auction archives, which are often found in auction catalogs).
Literature is also spreading knowledge about the history of a given money, i.e. why pennies were introduced into circulation, which transactions were used for thalers or ducats and how much did individual goods cost. It is also worth the reasons why some denominations have metal sheet defects? And often not only denominations, but the coinage of the entire ruler! Numismatics is also the study of the origin of old money, and in the case of medieval coins, assigning it to, for example, the rulers of individual districts after the breakdown of the country.
Most often, conscious collectors who want to expand their collections buy advanced catalogs for individual rulers or countries. Such literature is, for example, Bitkin for Russian coins, The Catalog of Coins of the Republic of Poland 1919 – 1939 or Monety by Stanisław August Poniatowski. There are also catalogs that are specialized not for individual countries or departments, but only for the denominations themselves! These are, for example, the catalog of the Orts of Sigismund III Vasa or the catalog of trojak coins by T. Iger.
In a word, something different for everyone
One thing is certain, an investment in literature pays off!