@book { TheStatedMotivationsfortheEarlyIslamicExpansion622641,
    title = "The Stated Motivations for the Early Islamic Expansion (622–641)",
    author = "Ayman S. {Ibrahim}",
    year = "2018",
    publisher = "Peter Lang Verlag",
    address = "New York, United States of America",
    doi = "10.3726/b11356",
    url = "https://www.peterlang.com/document/1054711"
}