@book { MonetreUmweltbewertungmitderContingentValuationMethode,
    title = "Monetäre Umweltbewertung mit der Contingent Valuation-Methode",
    author = "Ralf {Wagner}",
    year = "2000",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1090058"
}