Railroad Archives Online
- CollectionD0011 - James M. Fredrickson Collection
- Series003 - Great Northern Railway Company (U.S.)
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3006 - Cabooses (Railroads)
- ItemJMF14-05620.0 - Great Northern Railway wood caboose number X577, circa 1928.