2218-3620 2218-3620 S2218-36202020000600437 Ecuador 00 12 2020 00 12 2020 12 6 437 443

1998 2014 2010 1950 1968 1951 1955 1 1 1 3-23 2012 12 2 2 52-69 1995 1989 2012 2015 2002 1997