- Geological Survey (U.S.) (17)
- Fletcher, Hugh, 1848-1909 (9)
- Geological and Natural History Survey of Minnesota (7)
- A. Hoen & Co (6)
- New Jersey Geological Survey (6)
- Michigan. Geological Survey (5)
- Faribault, E. R. (Eugéne Rodolphe), 1860- (3)
- Geological Survey of Pennsylvania (3)
- Smock, John C. (John Conover), 1842-1926 (3)
- Stose, George Willis, 1869-1960 (3)
- Vermeule, C. C (3)
- Bayley, William Shirley, 1861-1943 (2)
- Bebb, E. C (2)
- Chamberlin, Thomas C. (Thomas Chrowder), 1843-1928 (2)
- Fowler, A. T (2)
- Geological Survey of Canada (2)
- Jenkins, Olaf P. (Olaf Pitt), 1889-1983 (2)
- Ku?mmel, Henry Barnard, 1867-1945 (2)
- Lesley, J. P. (J. Peter), 1819-1903 (2)
- University of Minnesota. Agricultural Experiment Station (2)