Version history for



  Hoffman, J.D., and Buttleman, Kim, 1994, National 
       Geochemical Database:  National Uranium Resource 
       Evaluation data for the conterminous United States:  
       U.S. Geological Survey Digital Data Series DDS-18-A.


  September 9, 2004
  Released online at
  http://pubs.usgs.gov/dds/dds-18-a/

  Version 1.0, 1994
  Intital release as a CD-ROM publication