Railroad Archives Online
- ArkivD0153 - Doug Wingfield Collection
- Serie004 - Northern Pacific Railroad Company
- Underserie014 - Photographs
- 001 - Railroads--Equipment and Supplies
- 004 - Railroad Passenger Cars
- ObjektWingfield.160 - Northern Pacific Passenger Car 558 at Seattle, Washington, 1962
- ObjektWingfield.161 - Northern Pacific Passenger Car at Seattle, Washington, 1962