APA (7e ed.) Bronvermelding

Gould, L. L. (1974). The progressive era. Syracuse University Press.

Chicago (17e ed.) Bronvermelding

Gould, Lewis L. The Progressive Era. Syracuse, N.Y: Syracuse University Press, 1974.

MLA (9e ed.) Bronvermelding

Gould, Lewis L. The Progressive Era. Syracuse University Press, 1974.