@book { Testibrevi,
    title = "Testi brevi",
    author = "Gudrun {Held} and Sabine {Schwarze}",
    year = "2011",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-00755-8",
    url = "https://www.peterlang.com/document/1044348"
}