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.

Xehetasun bibliografikoak
Erakunde egilea: U.S. Soil Conservation Service
Formatua: Liburua
Hizkuntza:English
Argitaratua: Washington, D. C. s.n. 1939.
Gaiak:
Soil conservation > United States.