APA
Zehler E, . (1981). potassuim Sulphate and Potasauim chloride - Their influence on the yield and quality of cultivated plants. : International Potash Institute., Switzerland.
Chicago
Zehler E, . 1981. potassuim Sulphate and Potasauim chloride - Their influence on the yield and quality of cultivated plants. : International Potash Institute., Switzerland.
Harvard
Zehler E, . (1981). potassuim Sulphate and Potasauim chloride - Their influence on the yield and quality of cultivated plants. : International Potash Institute., Switzerland.
MLA
Zehler E, . potassuim Sulphate and Potasauim chloride - Their influence on the yield and quality of cultivated plants. : International Potash Institute., Switzerland. 1981.