0188-6649 0188-6649 S0188-66492006000300083 10.21555/top.v31i1.185 Mexico 00 00 2006 00 00 2006 31 83 102

1998 2002 2003 1983 1991 1969 17 2 2 5-24 1993 107-27 1993 161-91 1996 2001 2003