1. Herrmann, M. and Goeb, O., Colour of gas-pressure-sintered silicon nitride ceramics Part I. Experimental data J. Eur. Ceram. Soc., 2001, 21(3), 303–314.
2. Göeb, O., Farbausbildungen und optische Inhomojenitäten beim Gasdrucksintern von Siliciumnitridkeramiken. Dissertation, TU Dresden, 2000.
3. Neidhardt, U., Partialdrucksintern von Siliziumnitrid, MPI Stuttgart, Dissertation, 1993.
4. Göb, O., Hermann, M., Siegel, S. and Obenaus, P., Origins and avoidance of colour inhomogeneites in silicon nitride ceramics. Key Engineering Materials, Trans Tech Publications Ltd, Zuerich, 1997, 132–136, 751–753.
5. Influence of sintering additives with differing proportions of Y2O3/A12O3 on the sintering and material properties of Si3N4 ceramics, cfi;Riedel;Ber. DKG,1998