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.

書誌詳細
団体著者: U.S. Soil Conservation Service
フォーマット: 図書
言語:English
出版事項: Washington, D. C. s.n. 1939.
主題:
Soil conservation > United States.