D3 1931 Effect of barley manuring on the following hay crop
D3 1931 Effect of barley row width on yield of hay
D3 1931 Effect of beet tops ploughed in for barley on the yield of the following hay crop
D4 1949 Nitrogen manuring of timothy for seed production
D4 1950 Nitrogen manuring of timothy for seed production
D4 1951 Nitrogen manuring of timothy for seed production