Preston, R. (1982). Teaching world understanding. Prentice-Hall.
Chicagoスタイル(17版)引用形式Preston, Ralph. Teaching World Understanding. New yark: Prentice-Hall, 1982.
MLA(9版)引用形式Preston, Ralph. Teaching World Understanding. Prentice-Hall, 1982.
警告: この引用は必ずしも正確ではありません.