1. E. P. Blizard, ?Shield optimization with respect to weight,? USAEC Reactor Handbook. Physics (McGraw-Hill, N. Y., 1955) Vol. 1, p. 709.
2. L. E. El'sgol'ts, The Calculus of Variations [in Russian] (Moscow-Leningrad, Gostekhizdat, 1952).
3. Materials of the USAEC. Reactor Shielding Design Manual.