1. Ashenfelter, Orley and John H. Pencavel. “American Trade Union Growth: 1900–1960.” Quarterly Journal of Economies 83 (August 1969): 434–48.
2. Bain, George Sayers and Robert Price. Profiles of Union Growth: A Comparative Statistical Portrait of Eight Countries. Oxford: Blackwell, 1995.
3. Barnett, George E. “American Trade Unionism and Social Insurance.” American Economic Review 23 (March 1933): 1–15.
4. Bernstein, Irving. “The Growth of American Unions.” American Economic Review 44 (June 1954): 301–18.
5. Bronfenbrenner, Kate, Sheldon Friedman, Richard W. Hurd, Rudolph A. Oswald, and Ronald L. Seeber, eds. Organizing to Win: New Research on Union Strategies. Ithaca, N.Y.: ILR Press, 1998.