Stock inventory cards are capable of filling a long-standing need for a simple and inexpensive system for the filing of references, papers and reprints in the spectrographic laboratory. The materials required consist of a number of 8½ in x 11 in stock file cards, a hole punch and a stacking frame. Each of these cards has a title line in the upper left corner as well as 7000 numbered squares on its face (Figure 1). This means that a total of 7000 references can be handled by the initial system; in order to expand the system, it is merely necessary to purchase a supply of cards of a different color. In addition, a series of 3 in x 5 in file cards and two filing cases to hold the cards are needed.
Theodore H. Zink, "Novel Cataloging System," Appl. Spectrosc. 15, 22-23 (1961)