1. R. Becker, F. Sauter andG. Heller:Zeits. Phys.,85, 772 (1933);F. London:Superfluids, Vol.1 (New York, 1950), p. 78.
2. A. F. Hildebrandt andM. M. Saffren:Proc. Conf. Low-Temp. Phys., 9th, Pt. A (1965), p. 459;C. A. King, jr.,J. B. Hendricks andH. E. Rorschach, jr.:Proc. Conf. Low-Temp. Phys., 9th, Pt. A (1965), p. 466;M. Bol andW. M. Fairbank:Proc. Conf. Low-Temp. Phys., 9th, Pt. A (1965), p. 471;J. B. Hendricks:Bull. Am. Phys. Soc., Series II,11 (2), 207 (1966).
3. H. Thirring:Phys. Zeits.,19, 33 (1918).
4. J. Lense andH. Thirring:Phys. Zeits.,19, 156 (1918).
5. B. S. DeWitt:Phys. Rev. Lett.,16, 1092 (1966).