[1] V. Bartošek R. Zezula: Flat Flux in a Slab Reactor with Natural Uranium. Journal of Nuclear Energy Parts A/B, 1966, Vol. 20, pp. 129-134.

[2] V. Bartošek R. Zezula: Stability of flat thermal Flux in a slab reactor. Apl. Mat. 13 (1968), 367-375. MR 0243795

[3] R. Zezula: A Sufficient Condition for the Flattening of Thermal Neutron Flux and Some Related Problems. (in onedimensional geometries). Apl. Mat. 14 (1969), 134-145.

[4] R. Bellman: Stability Theory of Differential Equations. Russian translation, Izd. Inostr. Lit., Moskva 1954. MR 0075365

[5] S. Lefschetz: Differential Equations: Geometric Theory. Interscience Publ., New York, London 1957. MR 0094488 | Zbl 0080.06401

[6] K. Meyer: Private communication (at the occasion of the Second German-Czechoslovak Colloquium on Reactor Physics, held at Baabe, Rügen, GDR, October 66). Zbl 1170.01377