2072-8174 2072-8174 S2072-81742016000200001 10.18004/rdn2016.0008.02.001-003 Paraguay 00 12 2016 00 12 2016 8 2 1 3 2000 2005 43 4 4 305-21 2001 2006 30 1 1 51-63 2012 1998 13 2 2