1. Recent advances in strain gauges;Higson;J.S.I.,1964
2. 3. Gall D C. Patent spec. 645.331 ‘Improvements in Strain Gauges and Methods of and Means for the production thereof; H.M. Patent Office, London (1944).
3. 4. Patent spec. 695.755 & 720.325 by Saunders-Roe Ltd and Jackson P. G. S., H.M. Patent Office, London, (195354).