See H. D. Nelson, ed., Area Handbook for Chad (1972); J. A. Works, Pilgrims in a Strange Land: Hausa Communities in Chad (1976); M. P. Kelley, State in Disarray: Conditions of Chad's Survival (1986); T. Collelo, Chad: A Country Study (2d ed. 1990); S. C. Nolutshungu, Limits of Anarchy: Intervention and State Formation in Chad (1996); M. J. Azevedo and E. A. Nnadozie, Chad: A Nation in Search of its Future (1997); S. Decalo, Historical Dictionary of Chad (3d ed. 1997); M. J. Azevedo, Roots of Violence: A History of War in Chad (1998); J. M. Burr, Africa's Thirty Years' War: Chad, Libya, and the Sudan, 1963–1993 (1999).