Railroad Archives Online
- CollectionD0036 - George Werkema Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1014 - Photographs
- Subseries Level 2001 - Railroads--Equipment and Supplies
- Subseries Level 3003 - Freight Cars
- 217 more...
- ItemWerkema349 - Northern Pacific ice-refrigerator car 207721 at the Northwest Railway Museum in Snoqualmie, Washington, in 2005.
- ItemWerkema350 - Northern Pacific refrigerator car NPM 496 at an unknown location in 1971.
- ItemWerkema351 - Northern Pacific stock car 82663 at Denver, Colorado, in 1971.
- ItemWerkema352 - Northern Pacific stock car 83149 at Broomfield, Colorado, in 1976.
- ItemWerkema353 - Northern Pacific stock car 83296 at Snoqualmie, Washington, in 2005.
- ItemWerkema354 - A wood NP stock car in Snoqualmie, Washington.