- Patent number 2,474,140. Page 1.
- Patent number 2,474,140. Page 2.
- Patent number 2,474,140. Page 3.
- Patent number 2,474,140. Page 4.
- Patent number 2,474,140.
- Patent number 2,474,140. Sheet 2
- Patent number 2,474,140. Sheet 3.
- The Proportional Governor Patent Number 2,474,140.
- Patent number 2,474,140. Sheet 4.
- Hamilton Standard history.
- HYDROMATIC PROPELLERS EQUIPPED EXCLUSIVELY WITH WOODWARD GOVERNORS.
- HYDROMATIC PROPELLER DEVELOPMENT HISTORY.
- HYDROMATIC PROPELLER DEVELOPMENT HISTORY.
- Some Hamilton Standard Company History.
- HYDROMATIC PROPELLER DEVELOPMENT HISTORY. PAGE 2.