Railroad Archives Online
- CollectionE0485 - Great Northern Railway Historical Society Railroad Forms Collection
- Series004 - Northern Pacific Railroad Company
- Subseries Level 1006 - Business Correspondence
- ItemNPform1331-TO-MOW-7x7.5 - Northern Pacific Form 1331, Train Order Form - Maintenance of Way Activities, 1967
- ItemNPform1740-CardTOformAB-4x6.125 - Northern Pacific Form 1740, Card Train Order Form, 1938
- ItemNPform1780-Envelope9.5x12.5 - Northern Pacific Form 1780, Envelope, undated
- ItemNPform608-RegisterTicket - Northern Pacific Form 608, Train Register Ticket, 1925