@book { HandbuchzurberuflichenWeiterbildung,
    title = "Handbuch zur beruflichen Weiterbildung",
    author = "Thieß {Petersen}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1089843"
}