@book { DieUkraineGrenzlandoderBrcke,
    title = "Die Ukraine – Grenzland oder Brücke?",
    subtitle = "Reflexionen zum aktuellen Konflikt",
    author = "Reinhard {Hildebrandt}",
    year = "2015",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-06292-2",
    url = "https://www.peterlang.com/document/1049999"
}