Version history for Raines, Gary L., 2001, revised 2006, Resource materials for a GIS spatial analysis course: U.S. Geological Survey Open-file Report 01-221, v. 1.1. [available on the World Wide Web at URL http://pubs.usgs.gov/of/2001/of01-221/ ]. Version 1. January 5, 2007 Revised the text to reflect refinements and updates in the lecture content that the author developed in the five years of classes he taught until his retirement. Version 1.0 December 21, 2006 Migrated to http://pubs.usgs.gov/of/2001/of01-221/ August 5, 2001 Initial release online at http://geopubs.wr.usgs.gov/open-file/of01-221/