0026-1742 0026-1742 S0026-17422015000600025 México México Mexico 00 12 2015 00 12 2015 58 6 25 31 1 2009 2 2010 21 6 6 912-9 3 2009 83 5 5 272-80 4 2010 84 1 1 39-48 5 2012 86 3 3 158-63 6 2009 83 6 6 360-5