1. Aronson, D., 1996. Overview of Systems Thinking. Thinking Page, pp. 3. .
2. AWWU, 1995. Anchorage Water and Wastewater Utility Annual Water Quality Report 1995.
3. Results of a reconnaissance trip to Mt. Etna, Italy: the effects of the 2002 eruption of Etna on the province of Catania;Barnard;Bulletin of the New Zealand Society for Earthquake Engineering,2004
4. Barnard, S.T., 2009. The Vulnerability of New Zealand Lifelines Infrastructure to Ashfall. Doctor of Philosophy thesis. University of Canterbury.
5. Volcanic Hazards: A Sourcebook on the Effects of Eruptions;Blong,1984