@book { SprachenundinterethnischeBeziehungeninEstlandinderUmbruchszeit,
    title = "Sprachen und interethnische Beziehungen in Estland in der Umbruchszeit",
    author = "Ekaterina {Popova}",
    year = "2017",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-07187-0",
    url = "https://www.peterlang.com/document/1050644"
}