@book { DieWahldesRentenalters,
    title = "Die Wahl des Rentenalters",
    author = "Peter {Schmidt}",
    year = "1995",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b14071",
    url = "https://www.peterlang.com/document/1068600"
}