@book { PrinzipPerspektivierung,
    title = "Prinzip Perspektivierung",
    author = "Zofia {Bilut-Homplewicz}",
    year = "2013",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-03775-3",
    url = "https://www.peterlang.com/document/1047921"
}