1. L. D. Landau and E. M. Lifshitz,Fluid Mechanics(Pergamon, Oxford, 1959), Chap. XVI.
2. I. M. Khalatnikov,An Introduction to the Theory of Superfluidity(Benjamin, New York, 1965), Chap. 13.
3. Second Sound in Liquid Helium II
4. G. B. Whitham,Linear and Nonlinear Waves(Wiley, New York, 1974), Chaps. 2 and 8.
5. T. N. Turner, Ph.D. thesis, California Institute of Technology, 1979.