Edward L. Nichols and Mary L. Crehore
Phys. Rev. (Series I) 2, 161 (1894) - Published 1 November, 1894
Frederick Bedell and Carl Kinsley
Phys. Rev. (Series I) 2, 170 (1894) - Published 1 November, 1894
H. S. Weber
Phys. Rev. (Series I) 2, 197 (1894) - Published 1 November, 1894