548 BELL SYSTEM TECHNICAL JOURNAL 



2. "Certain Topics in Telegraph Transmission Theory," H. Nyquist, A. I E E 



Trans., v. 47, 1928, pp. 617-44. 



3. "Certain Factors Affecting Telegraph Speed," H. Nyquist, A. I. E. E. Jour., 



V. 43, February 1924, pp. 124-30, and Bell Sys. Tech. Jour., v. 3, April 1924*, 

 pp. 324-46. 



4. "Measurement of Telegraph Transmission," H. Nyquist, R. B. Shanck, and S I 



Cory, A. I. E. E. Jour., v. 46, March 1927, pp. 231-40. 



5. "General Switching Plan for Telephone Toll Service," H. S. Osborne, A. I E E 



Trans., v. 49, 1930, pp. 1549-57, and Bell Sys. Tech. Jour., v. 9, Tuly 1930 

 |)p. 429-447. 



6. "Voice Frequency Carrier Telegraph System for Cables," B. P. Hamilton, II. 



Nyquist, M. B. Long, and W. A. Phelps, A. I. E. E. Jour., v. 44, March 19 '5 

 pp. 213-18. 



7. "Carrier Current Telephony and Telegraphy," E. H. Colpitis and O. B. Blackwell, 



A. I. E. E. Jour., V. 40, 1921, April, pp. 301-15, May, pp. 410-21, and June, 

 pp. 517-26. 



8. " Metallic Polar-Duplex Telegraph Svstem for Cables," John H. Bell, R. B. Shanck 



and D. E. Branson. A. I. E. E. Trans., v. 44, 1925, pp. 316-25. 



9. "Modern Practices in Private Wire Telegraph Service," R. E. Pierce, A. I E E 



Trans., v. 50, 1931, pp. 426-35. 



