Crain 1930, p. 186. Crain, G. D., ed. (1930), The Market data book: containing a directory of class, trade and technical publications, Chicago: G. D. Crain, LCCN21010316, OCLC7400259
Crain 1930, p. 186. Crain, G. D., ed. (1930), The Market data book: containing a directory of class, trade and technical publications, Chicago: G. D. Crain, LCCN21010316, OCLC7400259