@book { EntwurfeinerDressiergradregelung,
    title = "Entwurf einer Dressiergradregelung",
    author = "Matthias {Flach}",
    year = "2011",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783842812680",
    url = "https://m.diplom.de/document/228436"
}