2444-6483 2444-6483 S2444-64832019000400173 10.24875/end.19000019 Costa Rica 00 12 2019 00 12 2019 31 4 173 175

1 2009 35 3 3 397-404 2 1987 92 2 2 287-91 3 2017 40 43-6 4 2010 81 3 3 272-80 5 2014 32 9 9 1149.e1-3 6 2012 30 9 9 2091.e1-2 7 2017 60 3 3 204-8