Zadorozhko, A.; Chagovets, V.; Rudavskii, E.; Sheshin, G.; Kekutia, S.; Chkhaidze, N.; Mulders, N. The Features of the Collective Modes in Aerogels Filled With Superfluid Helium. Fiz. Nizk. Temp. 2009, 35, 962-967.