1870-199X 1870-199X S1870-199X2009000300136 10.22201/fo.1870199xp.2009.13.3.15575 Mexico Mexico Mexico 00 00 2009 00 00 2009 13 3 136 140

1 2002 28 10 10 684-8 2 2005 5 585-6 3 1999 7 261-4 4 1999 25 9 9 603-4 5 1999 15 28 6 2005 32 105-10 7 2008 41 3 3 219-26 8 2005 31 9 9 687-90 9 1996 22 9 9 471-3 10 2002 35 979-84 11 2002 28 638 12 1995 28 30 13 1997 23 508 14 1997 30 332 15 2005 38 928 16 1993 26 301