@book { MaxRegersMusik,
    title = "Max Regers Musik",
    author = "Hans-Peter {Retzmann}",
    year = "2015",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-04851-3",
    url = "https://www.peterlang.com/document/1048860"
}