@book { EinknfteausLeistungennach22Nr3EStG,
    title = "Einkünfte aus Leistungen nach § 22 Nr. 3 EStG",
    author = "Florian {Wenk}",
    year = "2016",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/b10615",
    url = "https://www.peterlang.com/document/1113806"
}