@book { DeutscheLehnwrterinderbulgarischenSprache,
    title = "Deutsche Lehnwörter in der bulgarischen Sprache",
    subtitle = "Phonetisch-phonologische und morphologische Besonderheiten",
    author = "Elka {Parveva-Kern}",
    year = "1999",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1087891"
}