Maksum, V. U. M., D. C. R. . Novitasari, and A. Hamid. “Image X-Ray Classification for COVID-19 Detection Using GCLM-ELM”. Jurnal Matematika MANTIK, vol. 7, no. 1, May 2021, pp. 74-85, doi:10.15642/mantik.2021.7.1.74-85.