@book { SpektralphotometrischeNitratbestimmunginnatrlichenGewssern,
    title = "Spektralphotometrische Nitratbestimmung in natürlichen Gewässern",
    author = "Guido G. {Juilfs}",
    year = "1998",
    publisher = "Diplom.de",
    address = "Hamburg, Deutschland",
    doi = "10.3239/9783832411855",
    url = "https://m.diplom.de/document/217105"
}