@book { AggressionasaChallenge,
    title = "Aggression as a Challenge",
    author = "Hanna {Liberska} and Marzanna {Farnicka}",
    year = "2016",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-05056-1",
    url = "https://www.peterlang.com/document/1048921"
}