Bell System Technical Journal Volume XXXV Number 2 March 1956 , Vol 35 No 2.
American Telephone & Telegraph Co, march 1956; pp 249-534; illus, photographs, refs; charts foldouts.
American Telephone & Telegraph Co, march 1956; pp 249-534; illus, photographs, refs; charts foldouts.
Bell Tel. Labs, NY issued June 1956 printed inside rear cover, published in Bell Sys. Technical Journal March 1956; 38 pages, diagrams, references.