1. Misner, C. (1969). Phys. Rev. Lett. 22, 1071.
2. Linde, A., Linde, D., and Mezhlumian, A. (1994). Phys. Rev. D49, 1783.
3. Zeldovich, Ya. B., and Novikov, I. D. (1983). Relativistic Astrophysics, Vol. 2: The Structure and Evolution of the Universe (Chicago University Press, Chicago).
4. Lifshitz, E. M., and Khalatnikov, I. M. (1963). Adv. Phys. 12, 185; (1963/64). Sov. Phys. Usp. 6, 495.
5. Belinski, V. A., Lifshitz, E. M., and Khalatnikov, I. M. (1971)/ Sov. Phys. Usp. 13, 745.