Version history for Thoms Evan E., and Haugerud, Ralph A., 2006, GDA (Geologic Data Assistant), an ArcPad extension for geologic mapping: Code, prerequisites, and instructions: U.S. Geological Survey Open-File Report 2006-1097 [available on the World Wide Web at URL http://pubs.usgs.gov/of/2006/1097/ ]. Version 1.0, May 5, 2006 Initial release online at http://pubs.usgs.gov/of/2006/1097/