Railroad Archives Online
- FondsD0036 - George Werkema Collection
- Cyfres004 - Northern Pacific Railroad Company
- Is-gyfres014 - Photographs
- 001 - Railroads--Equipment and Supplies
- 006 - Cabooses (Railroads)
- EitemWerkema358 - Northern Pacific steel caboose 10141 at Denver, Colorado, in 1970.
- EitemWerkema359 - Burlington Northern steel caboose 10050 at Longmont, Colorado, in 1989.
- EitemWerkema360 - Burlington Northern steel caboose 10050 at Longmont, Colorado, in 1989.
- EitemWerkema361 - Northern Pacific wood caboose 1238 at Seattle, Washington, in 1977.
- EitemWerkema362 - Northern Pacific wood caboose 1238 at Seattle, Washington, in 1977.
- 8 mwy...