Railroad Archives Online
- CollectionD0046 - Andrew Klamka Collection
- Series003 - Great Northern Railway Company (U.S.)
- Subseries Level 1004 - Library
- Subseries Level 2002 - Periodicals
- 45 more...
- ItemGNSemaphoreVol4No10 - 'Great Northern Semaphore' October 1927
- ItemGNSemaphoreVol4No11 - 'Great Northern Semaphore' November 1927
- ItemGNSemaphoreVol4No12 - 'Great Northern Semaphore' December 1927
- ItemGNSemaphoreVol5No1 - 'Great Northern Semaphore' January 1928
- ItemGNSemaphoreVol5No2 - 'Great Northern Semaphore' February 1928
- ItemGNSemaphoreVol5No3 - 'Great Northern Semaphore' March 1928
- ItemGNSemaphoreVol5No4 - 'Great Northern Semaphore' April 1928
- ItemGNSemaphoreVol5No5 - 'Great Northern Semaphore' May 1928
- ItemGNSemaphoreVol5No6 - 'Great Northern Semaphore' June 1928
- 6 more...