1405-3195 1405-3195 S1405-31952007000600701 Mexico Mexico Mexico Mexico 00 09 2007 00 09 2007 41 6 701 709

1999 183-202 2000 Chapingo, Edo. De Méx 440-54 2001 85-110 2004 38 555-64 2002 17 44-9 2004 México 59-78 2004 42 207-18 2001 1985 5ta 103-7 2007 45 25-40 2000 2004 42 55-70 2000 Segunda INEGI 1990 INEGI 2005 2003 37 85-94 1996 95-114 2003 5 1140-6 1999 SAS. Institute Inc. 1999 1967 6th 258-380 2003