0186-7210 0186-7210 S0186-72102006000300663 10.24201/edu.v21i3.1244 Mexico 00 12 2006 00 12 2006 21 3 663 700

1992 2004 13 1.1-1.20 2004 19 1 (55) 1 (55) 115-43 2002 233-42 1977 1996 1993 1994 1980 1 1977 1973 1994 1998 1 y 2 1996 1987 GDF 2000 1979 1996 1982 1994 14 14 1-19 1973 1960 1976 104-24 1993 1995 1961 1993 1998 18 321-39 1978 10 2 2 147-69 1983 3 3 57-83 1993 66 66 5-39 1948 55 189-208