@book { HeinrichHeineDichterPhilosophundEuroper,
    title = "Heinrich Heine - Dichter, Philosoph und Europäer",
    author = "Erzebet {von Gaal Gyulai}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1086513"
}