S. Y. Gultekin, H. Olgun, and M. S. Celiktas, “Comparison of solid biofuels produced from olive pomace with two different conversion methods: torrefaction and hydrothermal carbonization”, IJET, vol. 7, no. 2.23, pp. 143–147, Apr. 2018, doi: 10.14419/ijet.v7i2.23.11903.