APA (7th ed.) Citation

De Bono, E. (1991). Opportunities: A handbook of business opportunity search. Penguin Books.

Chicago Style (17th ed.) Citation

De Bono, Edward. Opportunities: A Handbook of Business Opportunity Search. London: Penguin Books, 1991.

MLA (9th ed.) Citation

De Bono, Edward. Opportunities: A Handbook of Business Opportunity Search. Penguin Books, 1991.