1990-8644 1990-8644 S1990-86442018000300159 República del Ecuador República del Ecuador República del Ecuador 00 06 2018 00 06 2018 14 63 159 163

(200 7) 101 1 1 59-68 (200 6) (200 0) (200 3) 21 1 1 7-43 (200 7) 10 61-82 (200 7) (199 6) (200 5) (200 1) 2 63-8 (201 3) (201 1) 6 51-5 (200 9) 323 5-7 (198 9) (200 4) (200 2)