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2. C.F. Klingshirn: Semiconductor Optics, 2nd corr. printing ( Springer, Berlin Heidelberg New York 1997 )
3. M. Kira, W. Hoyer, T. Stroucken, S.W. Koch: Phys. Rev. Lett. 87, 176401 (2001)
4. R.A. Kaindl, M.A. Carnaban, D. Hägele, R. Lövenich, D.S. Chemla: Nature 423, 734 (2003)
5. See e.g. J. Gutowski, H.G. Breunig, T. Voss: Dynamics of Excitons and Exciton Complexes in Wide-Gap Semiconductors,this book