Conservation of the soil; a unit for elementary schools developed by the Fairbrother-Rossell School, in cooperation with the Soil Conservation Service, USDA.

Conservation of the soil; a unit for elementary schools developed by the Fairbrother-Rossell School, in cooperation with the Soil Conservation Service, USDA.

Chi tiết về thư mục
Tác giả của công ty: U.S. Soil Conservation Service
Định dạng: Sách
Ngôn ngữ:English
Được phát hành: Washington, D. C. s.n. 1939.
Những chủ đề:
Soil conservation > United States.