@book { SchuldnerschutzinPolen,
    title = "Schuldnerschutz in Polen",
    subtitle = "Rechtsvergleichende Untersuchung eines universalen Regelungsproblems",
    author = "Christoph {Hellriegel}",
    year = "2007",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1103102"
}