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2. See, for instance, G. P. Agrawal and N. K. Dutta, Semiconductor Lasers (Van Nostrand Reinhold, New York, 1993).
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4. S. E. Kohn, P. Y. Yu, Y. Petroff, Y. R. Shen, Y. Tsang, and M. L. Cohen, Phys. Rev. B 8, 1477 (1973).
5. S.-H. Wei and A. Zunger, Phys. Rev. B 55, 13605 (1997).