Covello, V. T. and Merkhofer, M. W. 1993 Risk Assessment Methods Approaches for Assessing Health and Environmental Risks. Plenum, New York.

Fairman, R. and Mead, C. 1996 Approaches to Risk Assessment. Unpublished.

NAS 1983 Risk Assessment in the Federal Government: Managing the Process. US National Academy of Science, National Academy Press, Washington DC.