@book { SustainabilityLeadershipTraining,
    title = "Sustainability Leadership Training",
    author = "Tobias {Luthe}",
    year = "2007",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783836604642",
    url = "https://m.diplom.de/document/228961"
}