Gould, L. L. (1974). The progressive era. Syracuse University Press.
Chicagoスタイル(17版)引用形式Gould, Lewis L. The Progressive Era. Syracuse, N.Y: Syracuse University Press, 1974.
MLA(9版)引用形式Gould, Lewis L. The Progressive Era. Syracuse University Press, 1974.
警告: この引用は必ずしも正確ではありません.