 His earlier work was largely that of social history, including "The Great War and the British People" (1986) focuses on the war's demographic impact on the British population.In more recent works he has taken the approach of a cultural historian, most notably in "Sites of Memory, Sites of Mourning" (1995) where he advocates a more transnational focus for studying the war and European culture.In this book, he analyzes the various ways the people of Germany, France and Great Britain mourned their losses during and after the war.