@book { ControversyovertheExistenceoftheWorld,
    title = "Controversy over the Existence of the World",
    author = "Roman {Ingarden}",
    year = "2013",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-03767-8",
    url = "https://www.peterlang.com/document/1067462"
}