Legchenkova, I. V.; Silaeva, N. B.; Zoryansky, V. N.; Zinoviev, P. V.; Eremenko, V. V.; Avdeenko, A. A.; Yagotintsev, K. A.; Strzhemechny, M. A.; Stetsenko, Y. E.; Prokhvatilov, A. I.; Ruoff, R. S. Structure and Photoluminescence of Helium-Intercalated Fullerite C₆₀. Fiz. Nizk. Temp. 2002, 28, 1320-1323.