Bell System Technical Journal, Tables of Contents and Cumulative Index, volumes XI-XX, 1932-1941; AND, volumes XXI XXX, 1942 - 1951.
American Telephone & Telegraph Co, NY, n.d., ca. 1941 and 1952; 48 pages and 32 pages.
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.