1517-9702 1517-9702 S1517-97022018000100010 10.1590/s1517-970220184401001 Brazil 00 00 2018 00 00 2018 44 2008 20 1 1 221-36 2002 1996 2003 1 1 1 9-40 2006 9 2 2 15-32