1390-6542
1390-6542
S1390-65422017000400016
10.29019/enfoqueute.v8n4.169
Ecuador
00
09
2017
00
09
2017
8
4
16
26
[
2017
11
1
1
84 - 97
]
[
2005
1
]
[
2003
]
[
1999
]
[
2011
10
3
3
434-48
]
[
2016
83
1
1
72-80
]
[
2016
]
[
1994
234-44
]
[
1997
90-100
]
[
2016
11
7
7
5321-5
]
[
2006
]
[
2012
39
10
10
9554 - 9563
]
[
2014
]
[
2015
1591-6
]
[
2013
12
3
3
424-33
]