1817-5996 1817-5996 S1817-59962020000300016 Ecuador Ecuador Ecuador 00 12 2020 00 12 2020 22 3

1 2019 21 1^s1 1^s1 1 2 2017 19 3 3 3 2018 89 1 1 59-66 4 2017 19 1^s1 1^s1 1 213-9 5 2019 90 3 3 283-92 6 2019 21 1^s1 1^s1 1 7 2019 21 1^s1 1^s1 1 8 2019 21 1 1