1. Environmental Radioactivity in Denmark 1966. Danish Atomic Energy Commission;Aarkrog;Risö Report,1967
2. On the variation of the levels of 90Sr and other fallout nuclides in the grain of rye, barley, wheat and oats;Aarkrog,1968
3. Studies on plant absorption of Sr-90 and Cs-137 from some subtropical and tropical soils;Frederiksson;Försvarets Forksningsanstalt, FOA 4 Rapport,1963
4. Some applications for semi-conductor detectors in Health Physics;Lippert,1968
5. Radioactive strontium and caesium in the edible parts of crop plants after foliar contamination;Middleton;Intern. J. Radiation Biol.,1959