Swanson, D.A.; et al. (1989). "Mount Hood, Oregon". Cenozoic Volcanism in the Cascade Range and Columbia Plateau, Southern Washington and Northernmost Oregon: AGU Field Trip Guidebook T106, July 3–8, 1989. U.S. Geological Survey. Archived from the original on 3 February 1999. Retrieved 18 July 2013.
Swanson, D.A.; et al. (1989). "Mount Hood, Oregon". Cenozoic Volcanism in the Cascade Range and Columbia Plateau, Southern Washington and Northernmost Oregon: AGU Field Trip Guidebook T106, July 3–8, 1989. U.S. Geological Survey. Archived from the original on 3 February 1999. Retrieved 18 July 2013.