 | Soils Analysis. | (4) |
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 | Characteristics, interpretations and uses of Pennsylvania soils, Huntingdon County / R.W. Ranney ... . Ranney, R. W. (Richard Willard), 1936- University Park, Pa. : Pennsylvania State University, College of Agriculture, Agriculture Experiment Station, 1970. | |
| Characteristics, interpretations and uses of Pennsylvania soils : Armstrong County / R.L. Cunningham ... . University Park, Pa. : Pennsylvania State University, College of Agriculture, Agricultural Experiment Station, 1971. | |
| Characteristics, interpretations and uses of Pennsylvania soils, Northampton County / R.L. Cunningham ... . University Park, Pa. : Pennsylvania State University, College of Agriculture, 1969. | |
| Aggregate stability of soils from Western United States and Canada : measurement procedure, correlations with soil constituents / . Kemper, William Doral, 1928- 2n Washington : U.S. Dept. of Agriculture, 1966. | |
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