@book { Visualdifference,
    title = "Visual «difference»",
    author = "Elizabeth {Heffelfinger} and Laura {Wright}",
    year = "2011",
    publisher = "Peter Lang Verlag",
    address = "New York, United States of America",
    doi = "10.3726/978-1-4539-0055-0",
    url = "https://www.peterlang.com/document/1050874"
}