Abhandlungen über den mathematischen Unterricht in Deutschland /

c.2 v.1; v.1; Bd. 1, books 1-5; bd.1 ( heft 1-5) (1909); v.2; Bd. 2, books 1-8; v.3; Bd. 3, books 6-8; Bd. 3, books 1-5; v.3 pt.1-6 1911-1912; v.1 1909-1913; v.2 1910-1913; bd.2 ( heft 1-8) (1913); v.4; Bd. 4, books 5-9; Bd. 4, books 1-4; v.5; Bd. 5, books 1-4; c.2 v.5 pt.1; v.5 no.1-6 1912-1914; v.4 no.5-9 1911-1915; bd.3, pt. 1 ( heft 1-5) (1915); bd.4, pt. 2 (heft 5-9) (1915); bd.5, pt. 2 (heft 5-7) (1915); v.4 no.1-4 1910-1916; v.3 pt.7-9 1912-1916; bd.3, pt. 2, v.1 (heft 6-8) (1916); bd.3, pt. 2, v.2 ( heft 9) (1916); bd.5, pt. 1 (heft 1-4) (1916); Bd. 3, book 9