0187-893X 0187-893X S0187-893X2021000200021 10.22201/fq.18708404e.2021.2.76553 Spain Spain 00 00 2021 00 00 2021 32 2 21 36

2004 5 1 1 28-45 2008 2006 2012 23 4 4 432-50 European Commission 2015 2017 7 1 1 47-52 2015 33 2 2 231-52 2015 92 444-9 2009 10 1 1 71-80 2019 16 1 1 1501 2018 2019 968 30-9 Ministerio de Educación, Cultura y Deporte 2015 3 3 National Research Council 1996 National Research Council 2000 2012 30 94 94 67-86 2012 23 4 4 415-21 2016 52 2 2 161-97 2007 14 C23 C23 361-71 2018 5 3 3 375-86 2019 16 3 3 3501