1. F. WÖHLER, Organic Chemistry by P. KARRER translated by A. J. MEE, Elsevier, Amsterdam, London, Brussels, p. 917, 1947.
2. H. BECQUEREL, Compt. rend. Acad, Sci. Paris, 122 (1896) 501.
3. F. JOLIOT, I. CURIE, Nature, 133 (1934) 201.
4. F. JOLIOT, Nobel Lectures, Chemistry, 1922–1941, Elsevier, Amsterdam, London, New York, p. 369, 1966.
5. H. C. UREY, The Planets: Their Origin and Development, Yale University Press, New Haven, 1952.