@book { PsychotherapeutischeInterventionenbeiKrebskranken,
    title = "Psychotherapeutische Interventionen bei Krebskranken",
    author = "Jochen {Hefner}",
    year = "2021",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    url = "https://www.peterlang.com/document/1105455"
}