C. W. Waggoner
Phys. Rev. (Series I) 28, 393 (1909) - Published 1 June, 1909
R. H. Goddard
Phys. Rev. (Series I) 28, 405 (1909) - Published 1 June, 1909
Newland F. Smith
Phys. Rev. (Series I) 28, 429 (1909) - Published 1 June, 1909
R. E. Nyswander
Phys. Rev. (Series I) 28, 438 (1909) - Published 1 June, 1909
A. H. Pfund
Phys. Rev. (Series I) 28, 446 (1909) - Published 1 June, 1909