1. Changes in biotic conditions and metal deposition in the last millenium as reflected in ombrotrophic peat in Draved Moses, Denmark;Aaby;Geol. Surv. Denmark, Yearb.,1978
2. Trace Elements in the Terrestrial Environment;Adriano,1986
3. Analytical Atomic Absorption Spectroscopy;Aller,1987
4. Common micronutrients in plants;Aller;Información Técnica Económica Agraria (ITEA),1986
5. Geochemistry of trace elements;Aller,1988