Railroad Archives Online
- FondsD0046 - Andrew Klamka Collection
- Série003 - Great Northern Railway Company (U.S.)
- Sous-série004 - Library
- 002 - Periodicals
- 34 en plus...
- PièceGNSemaphoreVol3No11 - 'Great Northern Semaphore' November 1926
- PièceGNSemaphoreVol3No12 - 'Great Northern Semaphore' December 1926
- PièceGNSemaphoreVol4No1 - 'Great Northern Semaphore' January 1927
- PièceGNSemaphoreVol4No2 - 'Great Northern Semaphore' February 1927
- PièceGNSemaphoreVol4No3 - 'Great Northern Semaphore' March 1927
- PièceGNSemaphoreVol4No4 - 'Great Northern Semaphore' April 1927
- PièceGNSemaphoreVol4No5 - 'Great Northern Semaphore' May 1927
- PièceGNSemaphoreVol4No6 - 'Great Northern Semaphore' June 1927
- PièceGNSemaphoreVol4No7 - 'Great Northern Semaphore' July 1927
- 17 en plus...