1. BS 7910:2005. Guide to methods for assessing the acceptability of flaws in metallic structures.
2. API recommended practice 579, fitness for service,2000
3. Fitness for service procedure, FITNET, MK8,2008
4. Assessment of the integrity of structures containing defects, R6-revision 3,1999
5. Oil and gas pipeline systems, CSA Z662,2007