- WATCH YOUR CUTTERS
- CINCINNATI MILLERS
- The Carborundum Company.
- The Rockford Tool Company. 2
- American Machinist Magazine.
- THE JOHNSON FRICTION CLUTCH COMPANY.
- Rockford, Illinois manufacturing history.
- ALLIS-CHALMERS
- Union Twist Drill Company. 2
- Rockford, Illinois manufacturing history.
- Rockford 4.
- 7
- 11
- Rockford 3.
- 10