1. A. Abulencia, et al., hep-ex/0606027v1.
2. O. Bruning, in: CMS Workshop for SLHC, CERN, February 2004; D. Denegri, in: SLHC/VLHC Magnet Workshop, CERN, June 2006.
3. M. Barbero, et al., IEEE Trans Nucl. Sci. NS-52(4) 1187.
4. A. Vasilescu, in: DESY-Proceedings-1998-02, 1998.
5. V. Chiochia, et al., physics/0411143.