Railroad Archives Online
- CollectionD0153 - Doug Wingfield Collection
- Series003 - Great Northern Railway Company (U.S.)
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3006 - Cabooses (Railroads)
- ItemWingfield.53 - Great Northern Caboose X180 at Vancouver, British Columbia, 1968
- ItemWingfield.54 - Great Northern Caboose X505 at Spokane, Washington, 1968