Bell System Technical Journal volume XXXVII Number 5 september 1958; vol 37 no 5.
American Telephone & Telegraph Co, 1958; i-vi, pp 1091-1326, illus, photos, references.
American Telephone & Telegraph Co, 1958; i-vi, pp 1091-1326, illus, photos, references.
American Telephone & Telegraph Co, NY, n.d., ca. 1941 and 1952; 48 pages and 32 pages.
American Telephone & Telegraph Co, NY, n.d., ca. 1952; 32 pages.
AT&T 1965, pp 207-372 inclusive, diagrams and photographs, references.
Bell System, November 1970, pp 1995-2415 inclusive, diagrams, references, some photographs.