1990-8644 1990-8644 S1990-86442021000400338 Ecuador 00 08 2021 00 08 2021 17 81 338 344

2014 7 1 1 39-48 2009 48 2 2 63-9 2006 7 7 153-64 1991 73-95 2020 9 10 10 55-61 2007 11 2 2 1-23 2011 11 1 1 95-122 2012 2017 21 1 1 423-32