APA

Hill L. [., . (1991). <The >penguin english student's dictionary. London: Penguin.

Chicago

Hill L.H [ed.], . 1991. <The >penguin english student's dictionary. London: Penguin.

Harvard

Hill L. [., . (1991). <The >penguin english student's dictionary. London: Penguin.

MLA

Hill L.H [ed.], . <The >penguin english student's dictionary. London: Penguin. 1991.