1. Anon. 1996 Annual Book of ASTM Standards 957 980
2. Anon. 1996 Annual Book of ASTM Standards 981 1013
3. Anon. 1977 IC British Standards, BS 7448-1991 Fracture Mechanics Toughness Tests.
4. Anon. 1992 ESIS P1-92: Recommendations for Determining the Fracture Resistance of Ductile Materials; ESIS P2-92: ESIS Recommendations for Determining the Fracture Behaviour of Materials,
5. Anon. 1997 ISOCD 12135 Unified Method of Test for the Determination of Quasistatic Fracture Toughness (Draft-rev 3)