Webley, P.W., Dean, K.G., Dehn, Jonathan, Bailey, J.E., and Peterson, Rorik, 2010, Volcanic-ash dispersion modeling of the 2006 eruption of Augustine Volcano Using the Puff Model, chapter 21 of Power, J.A., Coombs, M.L., and Freymueller, J.T., eds., The 2006 eruption of Augustine Volcano, Alaska: U.S. Geological Survey Professional Paper 1769, p. 507-526 [http://pubs.usgs.gov/pp/1769/chapters/p1769_chapter21.pdf].
chapter PDF on USGS website