2218-3620 2218-3620 S2218-36202020000400270 Cuba Cuba 00 08 2020 00 08 2020 12 4 270 274

2015 2018 18 1 1 215-30 2017 1 1 1 2019 Cuba. Ministerio de Educación 2017 III 2019 2015 38 1 1 49-55 2019 2019 50 50 97-108 2019 23 1 1 108-18 2017 376 229-51 2019 11 11 1-12 2015 19 21 21 1-13