1. For example, see refs. Alkofer:2000wg,Roberts:2000hi,Roberts:2000aa,Holl:2006ni,Fischer:2006ub for recent reviews and references on various applications of the DS approach.
2. R. Alkofer, L. von Smekal, Phys. Rep. 353, 281 (2001).
3. C.D. Roberts, arXiv:nucl-th/0007054.
4. C.D. Roberts, S.M. Schmidt, Prog. Part. Nucl. Phys. 45, S1 (2000).
5. A. Höll, C.D. Roberts, S.V. Wright, arXiv:nucl-th/0601071.