Roberts, J. M. (. ). (1999). Twentieth century: The history of the world, 1901 to the present. London: Penguin Press.
Chicago Style CitationRoberts, John Morris (1928- ). Twentieth Century: The History of the World, 1901 to the Present. London: Penguin Press, 1999.
MLA CitationRoberts, John Morris (1928- ). Twentieth Century: The History of the World, 1901 to the Present. London: Penguin Press, 1999.
Warning: These citations may not always be 100% accurate.