1817-5996 1817-5996 S1817-59962020000400004 Ecuador 00 00 2020 00 00 2020 22

1 2014 14 1 1 109-16 2 2010 10 1 1 19-33 3 2009 4 1 1 18-25 4 2009 66 6 6 500-9 5 2001 1 1 1 18-21 6 2003 56 3 3 253-61 7 2011 64 11 11 988-96