2218-3620 2218-3620 S2218-36202018000200171 República del Ecuador República del Ecuador 00 02 2018 00 02 2018 10 2 171 174

1997 2009 14 2007 3 2 2 59-67 2003 International Organization for Standardization 2005 2017 9 1 1 1991 2012