M. A. DOLINSKI, A. C. V. MOTTA, B. M. SERRAT, and L. L. MAY-DE MIO, “pH, ELETRIC CONDUCTIVITY AND LEVELS POTASSIUM THIS SOIL AFTER THREE YEARS APLLIEDS NITROGEN AND POTASSIUM AT THIS PLUM, AT ARAUCARIA COUNTY PARANA – BRAZIL”, SA, vol. 10, no. 5, pp. 371–376, Sep. 2009.