Leffler, G. L. (1952). Seasonal changes in Pennsylvania business.
Chicagoスタイル(17版)引用形式Leffler, George Leland. Seasonal Changes in Pennsylvania Business. State College, 1952.
MLA(8版)引用形式Leffler, George Leland. Seasonal Changes in Pennsylvania Business. 1952.
警告: この引用は必ずしも正確ではありません.