1. B.L. Moldvasky, H.D. Kamisher:Compt. rend acad. sci. U.R.S.S.,1, 355 (1936).
2. V.I. Karshev, M.G. Severyanova, A.N. Siova:Khimiya Tverdogo Topliva (Chem. Solid Fuel),8, 559 (1936).
3. B.A. Kazanski, A.F. Plate:Ber.,69, 1862 (1936).
4. A.V. Grosse, J.C. Morrell, W.J. Mattox:Ind. Eng. Chem.,32, 528 (1940).
5. A.V. Grosse, J.C. Morrell: U. S. Patents 2,124,566, 2,124,567; 2,124,583; 2,124,584; 2,124,585; and 2,124,586; July, 1938.