Hughes, J. R. T. (1986). The vital few: The entrepreneur and American economic progress (Expanded ed.). Oxford University Press.
Lua i Stíl Chicago (17ú heag.)Hughes, Jonathan R. T. The Vital Few: The Entrepreneur and American Economic Progress. Expanded ed. New York: Oxford University Press, 1986.
Lua MLA (9ú heag.)Hughes, Jonathan R. T. The Vital Few: The Entrepreneur and American Economic Progress. Expanded ed. Oxford University Press, 1986.
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