850 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1952 



3. J. J. Pilliod and 11. L. Rvan, "Operator Toll Dialing," BcJl Td. Mag., 24, 



pp. 101-115, SumnuM- 1945. 



4. E. W. Baker, "Toll Dialing is Expanding Throughout the Nation," Bell Tel. 



Mag., 30, pp. 253-264, Winter 1951-52. 



5. F. F. Shipley, "Automatic Toll Switching Systems." Page 860 of this issue. 



6. C. A. Dahlhom, A. W. Horton, Jr. and D. "L. Moody, "Application of iMulti- 



frequencv Pulsing in Switching," A.I.E.E. Transactions, 68, pp. 392-396, 

 1949. 



7. N. A. Newell and A. Weaver, "Single-frequency Signaling System for Super- 



vision and Dialing over Long Distance Telephone Trunks," A.I.E.E. Trans- 

 actions, 70, (7 pages), 1951. 



8. Articles prepared by American Telephone and Telegraph Company for infor- 



mation of Dial Intere.xchange Committee of the United States Indejjendent 

 Telephone Association. Published in Telephony on dates indicated. 



a. Nationwide Operator Toll Dialing, January 12, 1946. 



b. New Toll Switching Plan for Nationwide Dialing, May 10 and 17, 1947. 



c. Nationwide Toll Dialing— Use of Tandem CDO's, July 3, 1948. 



