Sawaya. The Difficult Art of Giving. University of Pennsylvania Press.
Chicagoスタイル(17版)引用形式Sawaya. The Difficult Art of Giving. University of Pennsylvania Press.
MLA(8版)引用形式Sawaya. The Difficult Art of Giving. University of Pennsylvania Press.
警告: この引用は必ずしも正確ではありません.