- INGERSOLL MIILLING MACHINE COMPANY HISTORY.
- Philadelphia Gear Works
- INGERSOLL MILLING AND MANUFACTURING COMPANY HISTORY.
- Rockford, Illinois manufacturing history.
- Rockford, Illinois manufacturing history.
- INGERSOL MIILLING MACHINE COMPANY HISTORY.
- Rockford, Illinois history.
- Rockford, Illinois factory history.
- INGERSOLL MILLING MACHINE COMPANY
- Gears
- Foote Gears
- Fabroil gears
- INGERSOLL MILLING MACHINE COMPANY. c
- National Trwist Drill
- Gisholt Machine Company