APA

Palmer A., . (1979). The Penguin dictionary of twentieth century history. New York: Penguin Books.

Chicago

Palmer Alan, . 1979. The Penguin dictionary of twentieth century history. New York: Penguin Books.

Harvard

Palmer A., . (1979). The Penguin dictionary of twentieth century history. New York: Penguin Books.

MLA

Palmer Alan, . The Penguin dictionary of twentieth century history. New York: Penguin Books. 1979.