@book { UBootMaschinistFritzKastenEinFrontbuchderdeutschenKriegsmarine,
    title = "U-Boot-Maschinist Fritz Kasten - Ein Frontbuch der deutschen Kriegsmarine",
    author = "Ludwig {Freiwald} and EK-2 {Militär}",
    year = "2022",
    publisher = "EK-2 Publishing",
    address = ", Deutschland",
    url = "https://tolino.openpublishing.com/document/1278706"
}