- Rockford, Illinois manufacturing history.
- ALLIS-CHALMERS
- THE JOHNSON FRICTION CLUTCH COMPANY.
- The Foote Burt Drilling Machine Company
- Starrett Tools
- Rockford, Illinois manufacturing history.
- GENERAL ELECTRIC COMPANY
- American Machinist Magazine.
- Rockford 4.
- Rockford 3.
- The Rockford Tool Company. 2
- Rockford Tool Company.
- Union Twist Drill Company. 2
- Union Twist Drill Company
- BRADFORD MACHINE TOOL COMPANY.