The major contributor to this study has been Albert Pick who published some of the earliest catalogues of paper money and through them explained the objective of collecting paper money and the definition of it. Albert Pick is also the author of the capital part of the "Standard Catalog of World Paper Money", now a three-volume set which consists of thousands of pages of almost the entire collection of the world paper money that has ever existed and is updated annually. Almost every note of every country and many special and regional issues are cataloged following a unique format for each entry: NamePnumber for the banknote edition