The Production of Hyacinth Bulbs by David Griffiths, United States. Department of Agriculture, John Chambers McDowell, R. W. Leukel, Frank Heidtman Lathrop, M. A. Yothers, Walter Cochran Davis, Charles Sidney Leete, Ernst H. Wiecking, Donald Bruce, George Emil Heck, Fletcher Pearre Veitch, Frederick Charles Lincoln, Frank Getz Ashbrook, Arthur Vance Swarthout, David Segrid Olson, Elmer Lash, George Herbert Coons, H. F. Willard, Harold Coleman Hallock, Justus Watson Folsom, Ralph Henry Elsworth, Reginald D. Forbes, Wiley Croom Smith, William Gustavus Wahlenberg, Charles M. Harris, Dewey Stewart, Floyd Frank Bondy, Ira Burton Lanphier, Karl Burchard Hanson, Theodore Lemuel Bissell, William Melvin Mohler, Finley George Larmer