290 RUBIDIUM 



Rb-1. Fraser, D. A., and C. A. Mawson: Movement of Radioactive Isotopes in 

 Yellow Birch and White Pine as Detected with a Portable Scintillation Counter, 

 Can. J. Botany, 31: 324-333 (1953). 



Rb-2. Overstreet, Roy, and Louis Jacobson: The Absorption by Roots of Rubidium 

 and Phosphate Ions at Extremely Small Concentrati6ns as Revealed by 

 Experiments with Rb^^ and P'^ Prepared without Inert Carrier, Am. J. Botany, 

 33: 107-112 (1946). 



Rb-3. Higinbotham, N., H. Latimer, and R. Eppley: Stimulation of Rubidium 

 Absorption by Auxins, Science, 118: 243-245 (1953). 



Rb-4. Groenberg, David, Robert B. Aird, Muriel D. D. Boelter, W. Wesley Campbell, 

 Waldo E. Cohn, and Makio M. Murayama: A Study with Radioactive Iso- 

 topes of the Permeability of the Blood-Cerebrospinal Fluid Barrier to Ions, 

 Am. J. Physiol., 140: 47-64 (1943). 



