1. Gan, W.S.: Gauge invariance approach to acoustic fields. In: Akiyama, I. (ed.) Acoustical Imaging, vol. 29, pp. 389–394. Springer, Berlin (2007)
2. Fink, M.: Time reversal of ultrasonic fields—Part I. Basic principles. IEEE Trans. Ultrasons. Ferroelectr. Freq. Control 39(5), 1–12 (2006)
3. Kolmogorov, A.N.: The local structure of turbulence in incompressible viscous fluids for very large Reynolds numbers. Proc. USSR Acad. Sci. 30, 299–303 (1941)
4. Goldstone, J.: Field theories with superconductor solutions. Nuoco Cimento 19, 154–164 (1961)
5. Veselago, V.G.: The electrodynamics of substance with simultaneous negative values of ε and μ. Sov. Phys. Uspekhi 10(4), 509–514 (1968)