ATLAS OF TWENTIETH CENTURY WORLD HISTORY <i> by Michael Dockrill (HarperPerennial: $14.95).</i>

Although recent events in Eastern Europe already have rendered some of the clear, easy-to-read maps in this collection obsolete, they still can make the ongoing crises more comprehensible. A series of ethnic/linguistic maps sheds light on the internecine warfare among the breakaway Yugoslavian republics--and suggest future problems in restructuring the Soviet Union. In addition to offering a visual supplement to discussions of the 20th Century’s many wars, Dockrill offers a chapter devoted to maps and graphs describing political, social, economic and environmental problems. This useful volume demonstrates the truth of the old dictum: “To be understood, historical events must first be located.”