1870-199X 1870-199X S1870-199X2008000100029 10.22201/fo.1870199xp.2008.12.1.15698 Mexico Mexico Mexico 00 00 2008 00 00 2008 12 1 29 33

1. 2005 2 2006 141 1 1 433-42 3 1996 4 1990 97 4 4 289-300 5. 1982 6 1993 70 1 1 33-9 7 2004 27 1 1 91-100 8 2000 81 9 9 1137-42 9 2001 19 4 4 279-88 10 2001 28 12 12 1158-64 11 1982 45 4 4 343-7 12 1999 13 2 2 104-14 13 1994 21 1 1 33-45