APA
O c. J., . (1980). Better englih pronunciation 2nd ed. New York: Cambridge.
Chicago
O connar J.D, . 1980. Better englih pronunciation 2nd ed. New York: Cambridge.
Harvard
O c. J., . (1980). Better englih pronunciation 2nd ed. New York: Cambridge.
MLA
O connar J.D, . Better englih pronunciation 2nd ed. New York: Cambridge. 1980.