Railroad Archives Online
- FondiD0046 - Andrew Klamka Collection
- Serija003 - Great Northern Railway Company (U.S.)
- Podserija004 - Library
- 002 - Periodicals
- 52 more...
- DokumentGNSemaphoreVol5No5 - 'Great Northern Semaphore' May 1928
- DokumentGNSemaphoreVol5No6 - 'Great Northern Semaphore' June 1928
- DokumentGNSemaphoreVol5No7 - 'Great Northern Semaphore' July 1928
- DokumentGNSemaphoreVol5No8 - 'Great Northern Semaphore' August 1928
- DokumentGNSemaphoreVol5No9 - 'Great Northern Semaphore' September 1928
- DokumentGNSemaphoreVol5No10 - 'Great Northern Semaphore' October 1928
- DokumentGNSemaphoreVol5No11 - 'Great Northern Semaphore' November 1928
- DokumentGNSemaphoreVol5No12 - 'Great Northern Semaphore' December 1928