Educational Challenges, Inc. (1983). World geography. D.C. Heath.
Chicagoスタイル(17版)引用形式Educational Challenges, Inc. World Geography. Lexington, Mass: D.C. Heath, 1983.
MLA(9版)引用形式Educational Challenges, Inc. World Geography. D.C. Heath, 1983.
警告: この引用は必ずしも正確ではありません.