Four types of files are available here:

        *.dat   --    data files suitable for use with SAS
                      (ASCII text format; data only, no variable names)

        *.txt   --    data files suitable for use with Systat
                      (ASCII text format; variable names in first row)

        *.info  --    descriptions of datasets

        *.cbk   --    descriptions of datasets from Fox, "Applied
                      Regression Analysis"