00273    a2200109   4500082001700000100001800017245003900035250000900074260003100083300002400114650002500138  a005.756bSIM  aSimpson, Alan  aUnderstanding dBASE IV 1.5 for DOS  a3rd   aNew DelhibBPBc1993g1993  axlii, 1002p.c21cm.  aRELATIONAL DATABASES