Coulomb quantum kinetics of degenerate resonant femtosecond four-wave mixing Q. T. Vu, L. Bányai, P. I. Tamborenea and H. Haug Europhys. Lett., 40 3 (1997) 323-328 Published online: 01 September 2002 DOI: 10.1209/epl/i1997-00466-6