Many of the world's leading authorities in history, sociology, political science and psychology shed new light on the major genocides of the twentieth century. Featured authors include Irving Louis Horowitz, Helen Fein, Vahakn Dadrian, Roger W. Smith, Henry Huttenbach, Ervin Staub, and Turkish historian Taner Ak . The volume covers the genocides of the Armenians, Ukrainians, Jews, Gypsies, Rwandans and Bosnians, and also topics of genocide denial and prevention.