The Penguin dictionary of twentieth century history

MLA

Palmer, Alan Warwick. The Penguin Dictionary of Twentieth Century History. Harmondsworth: Penguin books, 1981.

APA

Palmer, A. Warwick. (1981). The Penguin dictionary of twentieth century history. Harmondsworth: Penguin books.

Chicago

Palmer, Alan Warwick, The Penguin Dictionary of Twentieth Century History. Harmondsworth: Penguin books, 1981.