@article{ribeiro_strecker_2004,  title={Si3N4 ceramics sintered with Y2O3/SiO2 and R2O3(ss)/SiO2: a comparative study of the processing and properties},  volume={7},  ISSN={1516-1439},  url={https://doi.org/10.1590/S1516-14392004000300003},  DOI={10.1590/S1516-14392004000300003},  number={3},  journal={Materials Research},  publisher={ABM, ABC, ABPol},  author={Ribeiro, Sebastião and Strecker, Kurt},  year={2004},  month={Jul},  pages={377–383} }