The mainspring of human progress.

APA Citation

Weaver, H. Grady., Lane, R. Wilder. (1953). The mainspring of human progress. [Rev. ed. of Mainspring] Irvington-on-Hudson, N.Y.: Foundation for Economic Education.

MLA Citation

Weaver, Henry Grady, 1889-1949, and Rose Wilder Lane. The Mainspring of Human Progress. [Rev. ed. of Mainspring] Irvington-on-Hudson, N.Y.: Foundation for Economic Education, 1953.