1. P. Danielewicz, Roy A. Lacey, P.-B. Gossiaux, et al., Phys. Rev. Lett. 81, 2438 (1998); C. Pinkenburg, N. N. Ajitanand, J. M. Alexander, et al., Phys. Rev. Lett. 83, 1295 (1999).
2. M. I. Adamovich, E. S. Basova, M. M. Chernyavsky, et al., Yad. Fiz. 60, 1580 (1997) [Phys. At. Nucl. 60, 1435 (1997)]; M. I. Adamovich, E. S. Basova, M. M. Chernyavsky, et al., Eur. Phys. J. A 6, 427 (1999); M. I. Adamovich, N. P. Andreeva, E. S. Basova, et al., Yad. Fiz. 67, 290 (2004) [Phys. At. Nucl. 67, 273 (2004)].
3. E895 Collab. (G. Rai, N. N. Ajitanand, J. Alexander, et al.), Nucl. Phys. A 661, 162 (1999); FOPI Collab. (A. Andronic, V. Barret, Z. Basrak, et al.), Phys. Lett. B 612, 173 (2005).
4. D. Brill, W. Ahner, P. Baltes, et al., Phys. Rev. Lett. 71, 336 (1993).
5. A. Pylos, Preprint CERN-2004-001, (Geneva, 2004); P. L. Jain, G. Singh, and A. Mukhopadhyay, Phys. Rev. Lett. 74, 1534 (1995);