Railroad Archives Online
- CollectionD0046 - Andrew Klamka Collection
- Series003 - Great Northern Railway Company (U.S.)
- Subseries Level 1004 - Library
- Subseries Level 2002 - Periodicals
- 39 more...
- ItemGNSemaphoreVol4No4 - 'Great Northern Semaphore' April 1927
- ItemGNSemaphoreVol4No5 - 'Great Northern Semaphore' May 1927
- ItemGNSemaphoreVol4No6 - 'Great Northern Semaphore' June 1927
- ItemGNSemaphoreVol4No7 - 'Great Northern Semaphore' July 1927
- ItemGNSemaphoreVol4No8 - 'Great Northern Semaphore' August 1927
- ItemGNSemaphoreVol4No9 - 'Great Northern Semaphore' September 1927
- ItemGNSemaphoreVol4No10 - 'Great Northern Semaphore' October 1927
- ItemGNSemaphoreVol4No11 - 'Great Northern Semaphore' November 1927
- ItemGNSemaphoreVol4No12 - 'Great Northern Semaphore' December 1927
- 12 more...