@book { RobertundClaraSchumanninihrenBeziehungenzuFranzLiszt,
    title = "Robert und Clara Schumann in ihren Beziehungen zu Franz Liszt",
    author = "Wolfgang {Seibold}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1099690"
}