"Dig where you stand" 6 proceedings of the sixth international conference on the history of mathematics education - Barbin, Évelyne 1949-; Kristín Bjarnadóttir; Furinghetti, Fulvia; Karp, Alexander; Moussard, Guillaume; Prytz, Johan; Schubring, Gert 1944- (Schriften zur Geschichte der Mathematik und ihrer Didaktik, 2020)