United States. Department of Agriculture, United States. National Archives and Records Service, Willits, M., Dabney, C. W., Brigham, J. H., Hays, W. M., . . . Vrooman, C. S. (1947). Letters sent by the assistant secretaries of agriculture, 1889-1919. National Archives.
Cita Chicago Style (17a ed.)United States. Department of Agriculture, United States. National Archives and Records Service, Mr Willits, Charles William Dabney, Joseph H. Brigham, W. M. Hays, B. T. Galloway, y Carl Schurz Vrooman. Letters Sent by the Assistant Secretaries of Agriculture, 1889-1919. Washington, [D.C.]: National Archives, 1947.
Cita MLA (8a ed.)United States. Department of Agriculture, et al. Letters Sent by the Assistant Secretaries of Agriculture, 1889-1919. National Archives, 1947.