[201]. Himstedt, Phys. Zeit. p. 476, 1900.
[202]. Henning, Annal. d. Phys. p. 562, 1902.
[203]. Kohlrausch and Henning, Verh. Deutsch. Phys. Ges. 6, p. 144, 1904.
[204]. Kohlrausch, Verh. Deutsch. Phys. Ges. 5, p. 261, 1904.
[205]. P. Curie, C. R. 134, p. 420, 1902.
[206]. Becquerel, C. R. 136, p. 1173, 1903.
[207]. Becquerel, C. R. 133, p. 199, 1901.
[208]. P. Curie, Société de Physique, March 2, 1900.
[209]. Joly, Phil. Mag. March, 1904.
[210]. S. and P. Curie, C. R. 129, p. 823, 1899.