1390-6542
1390-6542
S1390-65422018000400099
10.29019/enfoqueute.v9n4.403
Ecuador
00
12
2018
00
12
2018
9
4
99
109
[
2008
16-8
]
[
2014
]
[
2000
39
2
2
205-18
]
[
2001
2
1241-7
]
[
2015
]
[
2017
]
[
2013
879-83
]
[
2014
24
2
2
87-97
]
[
2013
3
2
2
]
[
2003
3
3023-8
]
[
1992
]
[
2017
]
[
2003
37
1
1
69-96
]
[
2001
178-86
]
[
2011
]