Revista de la Real Academia de Ciencias Exactas, Físicas y Naturales. Serie A. Matematicas. RACSAM (Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Mat. RACSAM) (20190101), 113, no.~4, 3785-3793. ISSN: 1578-7303 (print).eISSN: 1579-1505.
CERME11 Eleventh Congress of the European Society for Research in Mathematics Education Eleventh Congress of the European Society for Research in Mathematics Education, Utrecht University, Feb 2019, Utrecht, Netherlands www.cerme11.org