1. Do heavy metals prevent the agricultural use of municipal sludge;Jørgensen;Water Res.,1975
2. The Danish Soil Library;Lamm,1971
3. Standard Methods,1971
4. Cadmium availability to wheat. A study with radioactive trace under field conditions;Stenström;Ambio,1974
5. Physicochemical Processes for Water Quality Control;Weber,1972