1. BS 3846:1970 (1985) Methods for Calibration and Grading of Extensometers for Testing Metals.
2. BS 6888:1988 Methods for Calibration of Bonded Electrical Resistance Strain Gauges.
3. Burgess, M. C. (1986) Performance testing of bonded and weldable strain gauges at elevated temperatures, in Strain Measurement at High Temperature (ed. R. C. Hurst), Elsevier Applied Science, pp. 105–11.
4. EN 10002: Part 4:1994 Metallic Materials — Verification of Extensometers Used in Uniaxial Testing.
5. Furse, J. E. and Loveday, M. S. (1981) Improvements in or relating to extensometers. Patent 8131641 J X 5782.