1990-8644 1990-8644 S1990-86442020000400431 Ecuador 00 08 2020 00 08 2020 16 75 431 438

2015 13 2 2 5-26 2017 2007 2011 7 237-48 1991 2010 2007 100 177-202 2009 34 2009 8 23 23 119-38 1993 2007 2002 2020 1976 2006 58 27-39