Once that the number of Wyandotte-ASTM punched cards indexing spectral absorption data exceeded several thousand, it was necessary to use a more rapid method in order to obtain a reasonable speed of retrieval. A preclassification of the total deck is described which needs no other special equipment than a card sorting machine. With this method 2,836 cards must be handled in the most unfavorable case instead of the 42,000 representing the authors' collection.
R. Leysen and J. Van Rysselberge, "Preclassification System for the Wyandotte-ASTM Punched Cards, Indexing Spectral Absorption Data," Appl. Spectrosc. 19, 72-74 (1965)