United States. Department of Agriculture & Stefferud, A. (1962). After a hundred years. U.S. Govt. Print. Off.
Cita Chicago (17th ed.)United States. Department of Agriculture i Alfred Stefferud. After a Hundred Years. Washington: U.S. Govt. Print. Off, 1962.
Cita MLA (9th ed.)United States. Department of Agriculture i Alfred Stefferud. After a Hundred Years. U.S. Govt. Print. Off, 1962.
Atenció: Aquestes cites poden no estar 100% correctes.