APA (7th ed.) Citation

Palmer, A. (1964). A Dictionary of modern history: 1789-1945. Penguin books.

Chicago Style (17th ed.) Citation

Palmer, Alan. A Dictionary of Modern History: 1789-1945. London: Penguin books, 1964.

MLA (9th ed.) Citation

Palmer, Alan. A Dictionary of Modern History: 1789-1945. Penguin books, 1964.