0188-4999 0188-4999 S0188-49992016000400385 10.20937/rica.2016.32.04.02 Ecuador 00 11 2016 00 11 2016 32 4 385 397

2014 125 585-99 2015 3 40-8 APHA 2012 1360 ARCOM 2016 2005 2 323-32 2015 12 453-60 2007 373 363-82 2004 60 695-703 EPA 1996 2012 3 1542-50 Gobierno Provincial Autónomo de El Oro 2014 479 2011 409 5026-33 1980 14 975-1001 1981 13 211-25 2003 126 225-33 2007 55 459-68 2006 368 88-98 2013 29 165-78 2014 144 517-27 1993 23 2015 119 1289-95 2011 60 8-25 2013 90 333-7 2002 65 165-79 2003 17 3101-23 2000 29 484-91 2001 278 239-61