D. Hoàng Văn, A. Phạm, T. Lê, T. Nguyễn, T. Phan, and V. Trần, “Investigating the existence of oxygen interstitial in CuCr1􀀀xMgxO2 [0.00 X 0.30] thermoelectric materials by X-Ray photoelectron spectroscopy [XPS]”, Science & Technology Development Journal: Natural Sciences, vol. 5, no. 2, pp. 1125-1134, Apr. 2021.