APA

Crystal D., . (1994). An encyclopedia dictionary of language and langauges. London: Penguin books.

Chicago

Crystal David, . 1994. An encyclopedia dictionary of language and langauges. London: Penguin books.

Harvard

Crystal D., . (1994). An encyclopedia dictionary of language and langauges. London: Penguin books.

MLA

Crystal David, . An encyclopedia dictionary of language and langauges. London: Penguin books. 1994.