Ndung'u, S. N., et al. “Characterization of Amorphous Silicon Nitride Prepared from Sand and Coffee Husk Wastes by Carbothermal Reduction-Nitridation”. African Journal of Pure and Applied Sciences, vol. 4, no. 3, Dec. 2023, pp. 24-34, doi:10.33886/ajpas.v4i3.426.