1870-199X 1870-199X S1870-199X2007000100020 10.22201/fo.1870199xp.2007.11.1.15882 Mexico Mexico Mexico 00 00 2007 00 00 2007 11 1 20 23

1. 1992 338-43 2. 1977 72 128-46 3. 1984 28-36 4. 1980 657-69 5. 1985 175-86 6. 1988 484-90 7. 1992 8. 1992 9. 1988 103-16 10. 1984 86 224-32 11. 1990 247-58 12. 1980 78 89-92 13. 1988 484-90