2448-8089 2448-8089 S2448-80892018000200005 10.24844/em3002.00 00 00 2018 00 00 2018 30 2 5 7 2013 203-36 2017 48 4 4 342-7 2016 40 1 1 169-215 Education Committee of the European Mathematics Society 2011 81 46-8 2017 3769-75