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2. Potassium isotope fractionation in granite;Kobus,1966
3. Observations sur la composition isotopique du potassium de certaines roches;Letolle;C. R. Acad. Sci., Paris,1962
4. Variations in 39K41K ratio and movement of potassium in a granite-shale contact region;Schreiner,1965
5. Sodium self diffusion in natural minerals;Sippel;Geochim. Cosmochim. Acta,1963