[1]
P. Remeijer, S. C. Steel, R. Jochemsen, G. Frossati, і J. M. Goodkind, «On the properties of vacancies in solid 4 He as studied by pressure measurements», Fiz. Nizk. Temp., вип. 23, вип. 5-6, с. 586–597, Трав 1997.