1659-4940 1659-4940 S1659-49402018000200199 10.15517/c.a..v15i2.34833 El Salvador 00 12 2018 00 12 2018 15 2 199 218

2007 4 1 1 51-76 2011 1971 1983 2007 1997 2014 2015 14 14 1-24 2013 32 32 59-71 2008 2015 2014 25-44 2015 53-127 2015 267-334