1405-3195 1405-3195 S1405-31952018000300437 Mexico Mexico Mexico 00 05 2018 00 05 2018 52 3 437 453

1974 20 155-9 2013 18 89-103 2001 31 165-73 2002 48 7-23 2003 49 539-54 2000 46 116-26 1983 2004 201 145-60 1979 2 2006 40 521-32 2005 62 143-52 2006 52 262-72 2007 1998 23 9-19 2009 32 161-9 1825 115 513-85 1822 1999 61-98 2012 3 2011 32 135-45 2005 1935 4 189-282 2008 14 5-19 1993 1991 2015 49 439-54 R Development Core Team 2015 1959 10 290-300 2013 36 163-72 SAS Institute Inc 2002 1939 37 819-20 2014 2010 33 343-51 2013 47 91-106