1. Variations in concentration of radiocarbon with time and location on earth;De Vries;Koninkl. Ned. Acad. Wetensch. Proc.,1958
2. Radiocarbon and climate;Damon;Meteorological Monographs,1968
3. Cosmic-ray intensity and geomagnetism;Elsasser;Nature,1956
4. History of radiocarbon dating;Libby,1967
5. Climatic versus magnetic perturbation of the atmospheric carbon 14 reservoir;Damon,1968