1. B. Sehgal, Nucl. Sci. and Engng.,27, 95 (1967).
2. J. Weitman, Nucl. Sci. and Engng.,18, 246 (1964).
3. E. Hellstrand, in: Reactor Physics in Resonance and Thermal Regions, Vol. 2, MIT Press, Cambridge (1966), p. 151.
4. V. P. Rukhlo and L. N. Topil'skii in: Nuclear Reactor Physics [in Russian], No. 2, Atomizdat, Moscow (1970), p. 187.
5. G. I. Khlebnikov and E. P. Dergunov, At. Energ.,9, No. 5, 406 (1960).