@book { MotivationandSecondLanguageAcquisition,
    title = "Motivation and Second Language Acquisition",
    subtitle = "The Socio-Educational Model",
    author = "Robert {Gardner}",
    year = "2010",
    publisher = "Peter Lang Verlag",
    address = "New York, United States of America",
    url = "https://www.peterlang.com/document/1135826"
}