@book { DieBerufskombinationinderBerglandwirtschaft,
    title = "Die Berufskombination in der Berglandwirtschaft",
    author = "Walter {Schläppi}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Lausanne, Switzerland",
    url = "https://www.peterlang.com/document/1070116"
}