1. An improved type of pressure tester for the determination of fruit maturity;Magness;U.S.D.A. Circ. No. 350,1925
2. Studies on punch testing of apples;Bourne;Fd Technol.,1965
3. Analysis of the mechanics of the fruit pressure tester;Yang;J. Texture Studies,1974
4. Fruit pressure testers and their practical application;Haller;U.S.D.A. Circ. No. 627,1941
5. Vibration techniques for measuring fruit firmness;Finney;J. Texture Studies,1972