1. Ralph E K and Klein Jeffrey , 1979, Composite computer plots of 14C dates for tree-ring dated bristlecone pines and sequoias, in Berger, Rainer and Suess, H E, eds, Radiocarbon dating, Internatl radiocarbon conf, 9th, Proc: Berkeley/Los Angeles, Univ California Press, 545–553.
2. Variations in the atmospheric radiocarbon concentration over the past 1300 years;Willis;Radiocarbon,1960
3. Radiocarbon-calendar age relationship
4. Accuracy of the Radiocarbon Time Scale Beyond 15,000 BP