Vescoli, V., Degiorgi, L., Buschinger, B., Guth, W., Geibel, C., & Steglich, F. (1998). THE OPTICAL PROPERTIES OF RuSi: KONDO INSULATOR OR CONVENTIONAL SEMICONDUCTOR? Solid State Communications, 105(6), 367-370. doi:10.1016/S0038-1098(97)10147-8.