@book { TPM,
    title = "TPM",
    subtitle = "Effiziente Instandhaltung und Maschinenmanagement",
    author = "Edward H. {Hartmann} and Dagmar {Beese}",
    year = "2013",
    publisher = "Vahlen",
    address = "München, Deutschland",
    url = "https://vahlen.openpublishing.com/document/1221265"
}