Walter Raymond Humphries

Alexander Campbell Martin, Arthur Henry Senner, C. C. Plummer, C. H. Hadley, Chalmers Jackson King, Curtis Paul Clausen, David A. Savage, Ernest Victor Abbott, Frederick Charles Lincoln, Glenn Gardner Hahn, Harold Francis Scholz, Harold Glenn Meginnis, J. Clark Salyer, James Herbert Beattie, Jenkin William Jones, Mayne Reid Coe, Paul William Miller, Ralph P. Hotis, Robert J. Sim, United States. Department of Agriculture, Walter Ernest Fleming, Wilbur Clifford Edmundson, Wilbur Magruder Hurst, Claude Hope, Frederick William Metzger, Ira Myron Hawley, James Robert McCalmont, John Walter Taylor, Victor Rickman Boswell, Walter Raymond Humphries, William Ernest Stone, E. E. Hall, Max Raymond Osburn, Roland McKee · Yayınevi bilinmiyor

610 sayfa · 1934

Agriculture

Wilbur Magruder Hurst · Yayınevi bilinmiyor

24 sayfa · 1935

Cereal smut diseases

George W. Collier, Walter Raymond Humphries, Earl W. McComas · Yayınevi bilinmiyor

32 sayfa · 1928

Agriculture

Wilbur Magruder Hurst, Walter Raymond Humphries, Roland McKee · Yayınevi bilinmiyor

8 sayfa · 1934

Agricultural machinery

Earl Wooddell Sheets, A. W. McKay, Altus Lacy Quaintance, Benton E. Rothgeb, Charles E. Chambliss, Charles Vancouver Piper, Curtis Hernon Kyle, David Leroy Yarnell, Frank Getz Ashbrook, George A. Lawyer, , · Yayınevi bilinmiyor

Morris Cotgrave Betts · Yayınevi bilinmiyor

28 sayfa · 1931

Farm layout

Le Roy August Reynoldson, Walter Raymond Humphries, John Holmes Martin · Yayınevi bilinmiyor

60 sayfa · 1931

Agriculture

Wilbur Magruder Hurst, Walter Raymond Humphries, Roland McKee · Yayınevi bilinmiyor

32 sayfa · 1935

Legumes

Harry Elmer Besley · Yayınevi bilinmiyor

36 sayfa · 1941

Grass

Charles Ford Langworthy, B. R. Coad, C. J. Babcock, Cecil Calvert Thomas, Charles Dwight Marsh, Clyde Ray Chambers, Don Divance Lescohier, Ellis Lore Kirkpatrick, Frank Barnes Herbert, · Yayınevi bilinmiyor

Wilbur Magruder Hurst, Walter Raymond Humphries · Yayınevi bilinmiyor

44 sayfa · 1938

Combines (Agricultural machinery)

Evelyn V. Clark, Walter Raymond · Yayınevi bilinmiyor

Sayfa sayısı yok · 1933

Kategori yok

Ernest John George, George Henry Hepting, Le Roy August Reynoldson, Leander D. Howell, Paul Random Henson, Harvey Leroy Westover · Yayınevi bilinmiyor

48 sayfa · 1935

Alfalfa

A. F. Burgess, Alonzo Clayton Davis, B. L. Wade, Bascom Anthony Belcher, C. C. Plummer, Charles Edwin Kellogg, Clarence Elbert Clement, Ellsworth Zouave Russell, Frank R. Smith, Harold Glenn Meginnis, James William Park, · Yayınevi bilinmiyor

Alfred Douglas Edgar, Leonard Lee Harter, Mark Hughlin Haller, Ralph Erskine, Walter Raymond Humphries, Albert Lloyd Ryall, Thomas Arrington Huntington Miller, William John Zaumeyer, Bryan Lewellyn Wade, Edwin Smith · Yayınevi bilinmiyor

32 sayfa · 1942

Apples

United States. Bureau of Agricultural Economics · Yayınevi bilinmiyor

26 sayfa · 1927

Harvesting machinery

Walter Raymond Humphries · Yayınevi bilinmiyor

Sayfa sayısı yok · 1942

Agricultural machinery