| [1] The Morkrum Printing Telegraph | Charles Krum & Howard Krum, 1911 |
| [2] A Brief History of The Morkrum Company |
Howard L. Krum, 1925 |
| [3] The Teletype Story |
Teletype Corporation, 1958 |
| [4] History of Teletypewriter Development |
R.A. Nelson and K.M. Lovitt, 1963 |
| [5] History of Telegraphy from the Teletype Museum |
Ransom D. Slayton, 1983 |
|
[6] The Early Years of Teletype Development A Patent History |
Ransom D. Slayton; 1983? |
| [7] Telex and TWX History |
Donald E. Kimberlin, 1986 |
| [8] History of Mark and Space |
Harvey, 1990 |
| [9] AT&T Exits Telegraph Business |
AT&T Press Release, 1991 |
| [10] Some Notes on Teletype Corporation |
Jim Haynes, 2001 |
| [11] A Synopsis of Teletype Corporation History |
Don Robert House, 2001 |
| [12] Teletypewriter Communication Codes |
Gil Smith, 2001 |