1. Collins dictionary of the English language,1979
2. Norsk Standard NS5814. 1991. Krav til risikoanalyser, Norges Standardiseringsforbund (NSF).
3. Control of risk: a guide to the systematic management of risk from construction;Godfrey,1996
4. British Standard BS8444-3: 1996 (IEC 300-3-9: 1995). Risk management: Part 3—guide to risk analysis of technological systems. British Standards Institute.
5. National Standard of Canada CAN/CSA-Q850-97. 1997. Risk management: guideline for decision-makers. Canadian Standards Association.