APA
De Bono E., . (1991). The 5 day course in thinking. London: Penguin books.
Chicago
De Bono Edward, . 1991. The 5 day course in thinking. London: Penguin books.
Harvard
De Bono E., . (1991). The 5 day course in thinking. London: Penguin books.
MLA
De Bono Edward, . The 5 day course in thinking. London: Penguin books. 1991.
