1. International Standardisation Organisation/Technical Committee 5/SC 6.
2. Chemistry & Industry;Cowley,1978
3. Plastic Gas Pipes — Fracture Considerations — Paper 3;Greig,1973
4. L. Ewing, Plastics in Gas Distribution (Paper 6).
5. E. Gaube and W. Muller, Rapid Crack Propagation and Crack Arrest on PE50 Pipes Under Internal Gas Pressure (Paper 22)