I. Adamenko, K. Nemchenko, V. Slipko, і A. Wyatt, «Collective modes in superfluid helium when there is a relative velocity between the normal and superfluid components: Жидкий гелий», Fiz. Nizk. Temp., вип. 34, вип. 4-5, с. 357–366, Бер 2008.