@book { DiebedrfnisorientierteVersorgungswirtschaft,
    title = "Die bedürfnisorientierte Versorgungswirtschaft",
    author = "Alfred {Fresin}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1100033"
}