APA

Greene G., . (1991). The Heart of the Matter. New York: Penguin books.

Chicago

Greene G, . 1991. The Heart of the Matter. New York: Penguin books.

Harvard

Greene G., . (1991). The Heart of the Matter. New York: Penguin books.

MLA

Greene G, . The Heart of the Matter. New York: Penguin books. 1991.