1405-9436 1405-9436 S1405-94362007000200167 Mexico 00 00 2007 00 00 2007 3 26 167 204

1990 1974 15 1990 1992 1988 28 1981 97 1998 33 1999 1989 68 1999 1989 72 1997 167 1984 38 1988