0121-7488 0121-7488 S0121-74882018000200095 Colombia Colombia 00 12 2018 00 12 2018 9 2 95 98

[1] 2014 50 1 1 39-45 [2] 2001 92 5 5 830-9 [3] 2004 374 1 1 112-5 [4] 2006 408 551-5 [5] 2008 451 1 1 627-31