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 Telephone System technical publications, Monograph 2032, issued Jnauary 1953; 8 pages, double-column text, diagrams, references.