82 RADIOISOTOPES IN BIOLOGY AND AGRICULTURE 



56. Buchanan, D. L., Akira Xakao, and George Edwards: Carbon Isotope Effects in 

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57. Ropp, Giis A.: Effect of Isotope Substitution on Organic Reaction Rates, Nucle- 

 onics, 10: 22-27 (1952). 



58. Myerson, Albert L., and Farrington Daniels: Relative Rates of Hydrolysis of 

 Urea Containing C'^ and C^\ Science, 108: 670 (1948). 



59. Yankwirh, Peter E. : Isotope Effects in Chemical Reactions, Ann. Rev. Nuclear 

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