About Denis Clark Denis Clark, DPhil, has published in Nations and Nationalism, The International History Review, and Studia Historyczne, and has taught at the University of Oxford and the University of Calgary. Books by Denis Clark Passion and Restraint Poles and Poland in Western Diplomacy, 1914-1921 by (author) Denis Clark Passion and Restraint Poles and Poland in Western Diplomacy, 1914–1921 by (author) Denis Clark