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3. F. Wuilleumier, “Contribution a L’Etude de la Photoionisation des Gaz Rares par Analyse Continue Entre 1,5 et 15 A,” Thesis, University of Paris, 1969.
4. United States Committee on Extension to the Standard Atmosphere, U. S. Standard Atmosphere, 1962, Superintendent of Documents, U. S. Government Printing Office, Washington, D. C.
5. E. J. McGuire, “Photo-Ionization Cross Sections of the Elements Helium to Xenon,” Phys. Rev. 175:20–30 (1968).