1657-6357 1657-6357 S1657-63572020000100184 10.25100/sye.v0i39.8322 Colombia 00 04 2020 00 04 2020 39 184 189 1970 1996 2001 1969 6 3 3 167-91 1976 1985 1998 1935 2012 14 27 27 172-6 2003 5 5 109-24 1995 2008 1998 1997 1997 293-334 2001 49 49 17-23