@book { Adpersonam,
    title = "Ad personam",
    author = "Dirk {Jäckel} and Gerhard {Lubich}",
    year = "2019",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b15754",
    url = "https://www.peterlang.com/document/1111072"
}