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 3004 - Railroad Passenger Cars
- ItemWingfield.43 - Great Northern Budd Observation Car "Saint Nicholas Mountain" at Hamilton, Ontario, July 15, 1962.
- ItemWingfield.107 - An old Great Northern parlor car at Essex, Montana, May 24, 1971.