APA
Humphry Derek, Ward Michael, . (1974). Passports and politics. London: Penguin Books.
Chicago
Humphry Derek, Ward Michael, . 1974. Passports and politics. London: Penguin Books.
Harvard
Humphry Derek, Ward Michael, . (1974). Passports and politics. London: Penguin Books.
MLA
Humphry Derek, Ward Michael, . Passports and politics. London: Penguin Books. 1974.