Soil, the most valuable mineral resource
Subtitle: its origin, destruction and preservation
By: by W. H. Twenhofel.
Series: Oregon. State Dept. of Geology and Mineral Industries. Bulletin; no. 26
Published: 1944
Place of publication: [Portland
Language: eng
Number of pages: 45
Subjects: Erosion.; Soil conservation.
Notes: "References cited": p. [46]-[47]
Reproduced from type-written copy.