1. Gilliam H.K. and M.P. Whittaker, Ext. Abs. 11th Biennial Conf. on Carbon, American Carbon Society, Gattlinburg, 211 (1973).
2. Kasatochkin V.I., V.V. Korshak, Yu.P. Kudryavtsev, A.M. Sladkov and I.E. Sterenberg, Carbon, 11, 70 (1973).
3. Bragg W.H. and W.L. Bragg, Proc. Roy. Soc., (London) 89, 277 (1913).
4. Ergun S., Chemistry and Physics of Carbon, Ed. P.L. Walker Jr., Marcel Dekker N.Y., 3, 211 (1968).
5. Debye P. and P. Scherrer Physik Z., 18, 291 (1917).