2007-0934 2007-0934 S2007-09342015000801743 México 00 12 2015 00 12 2015 6 8 1743 1756

2003 29 2 2 155-68 2012 46 37-52 2000 92 283-8 2007 4 1 1 25-40 1990 143-7 1996 14 150-8 1986 2008 26 43-52 2004 129 201-14 2009 2005 39 431-9 2006 24 1 1 49-61 1991 2004 2006 2006 40 1 1 27-38 2000 2007 2012 3 7 7 1389-400 1982 2003 26 75-80 2007 33 2 2 145-51 2007 76 169-85 2010 28 381-90 Statistics. Version 8. SAS Inst. 19 749-56 2010 1 2 2 149-58 2000 34: 1969 7 269-76 2002 94 326-30