0186-7210 0186-7210 S0186-72102006000100211 10.24201/edu.v21i1.1267 Mexico 00 04 2006 00 04 2006 21 1 211 225

1999 2001 2002 1993 1994 2001 1992 1997 XV 51 51 71-83 1996 2000 1986