@book { WievielEventbrauchteinEventSchauplatzHospitality,
    title = "Wieviel Event braucht ein Event - Schauplatz Hospitality",
    author = "Alexander {Wolf}",
    year = "2003",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832468897",
    url = "https://m.diplom.de/document/222229"
}