@book { SchuleundUmwelterziehung,
    title = "Schule und Umwelterziehung",
    author = "Christoph {Berchtold} and Martin {Stauffer}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    url = "https://www.peterlang.com/document/1085991"
}