@book { HeinrichBehnke18981979ZwischenMathematikundderenDidaktik,
    title = "Heinrich Behnke (1898-1979) – Zwischen Mathematik und deren Didaktik",
    author = "Uta {Hartmann}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1106913"
}