Electronic and optical properties under pressure effect of alkali metal oxidesM. Moakafi, R. Khenata, A. Bouhemadou, H. Khachai, B. Amrani, D. Rached and M. RératEur. Phys. J. B, 64 1 (2008) 35-42DOI: https://doi.org/10.1140/epjb/e2008-00286-6