- A Rasdon Tangential Water Wheel advertisment from 1902.
- A Pelton Water Wheel Company advertisement from 1902.
- A Risdon Iron Works advertisement from 1902.
- The Pelton Water Wheel Company History, circa 1902.
- Kern River Hydro Plant Governor Unit.
- Woodward Governor Company ad from 1925.
- Engineering News-Record History
- 4
- The Journal of Electricity Power and Gas .
- 10
- 7
- 11
- 13. ca. 1902.
- 3
- 2