CalderA. B. and VossR. C., “The Sampling of Hill Soils and Herbage with Particular Reference to the Determination of the Trace Elements,” Bull. No. 1, (Consultative Comm. for Devel. of Spectrographic Work, Aberdeen, Scotland, 1957) pp. 16–30.
3.
ShermanJ., Physical Methods in Chemical Analysis, BerlW. G., Ed. (Academic Press Inc., New York, 1950), p. 327.
4.
De LaffolieH., Spectrochim. Acta11, 401–408 (1956).