O'Driscoll, J. (1990). Penguin basic English grammar exercises with answers. Penguin Books.
Chicago Style (17th ed.) CitationO'Driscoll, James. Penguin Basic English Grammar Exercises with Answers. Wright Lane, London: Penguin Books, 1990.
MLA (9th ed.) CitationO'Driscoll, James. Penguin Basic English Grammar Exercises with Answers. Penguin Books, 1990.
Warning: These citations may not always be 100% accurate.