2072-8174 2072-8174 S2072-81742018000100131 10.18004/rdn2018.0010.01.131-134 Paraguay Paraguay Paraguay Paraguay 00 06 2018 00 06 2018 10 1 131 134

1 2002 37 211 211 144-8 2 1987 69 5 5 778-80 3 2003 37 1 1 33-40 4 2001 66 3 3 179-86