@book { TheFourthSelf,
    title = "The Fourth Self",
    author = "Richard E. {Trull}",
    year = "2016",
    publisher = "Peter Lang Verlag",
    address = "New York, United States of America",
    doi = "10.3726/978-1-4539-1138-9",
    url = "https://www.peterlang.com/document/1051134"
}