@book { FirstLanguageversusForeignLanguage,
    title = "First Language versus Foreign Language",
    author = "Esther Odilia {Breuer}",
    year = "2015",
    publisher = "Peter Lang Verlag",
    address = "Berlin, Germany",
    doi = "10.3726/978-3-653-04262-7",
    url = "https://www.peterlang.com/document/1048045"
}