1. G. D. Shilling, B. Tooney, and W. Kraus, Gasification of Coal [in Russian], Nedra, Moscow (1986).
2. M. S. Orenbach, Reaction Surface in Heterogeneous Combustion [in Russian], Novosibirsk, Nauka (1973).
3. N. M. Laurendeau, ?Heterogeneous kinetics of coal char gasification and combustion?, Progr. Energy Combust. Sci., No. 4, 221 (1978).
4. K. L. Batarseh, G. P. Swaney, and A. H. Stiller, ?A mathematical model for heterogeneous reactions with a moving boundary?, AIChE J.,35, No. 4, 25 (1989).
5. J. Shekely and W. E. Evans, ?A structural model for gas-solid reactions with a moving boundary?, AIChE J.,35, No. 4, 25 (1989).