1. J. Christen and D. Bimberg, Phys. Rev. B 42, 7213 (1990).
2. D. S. Sizov, V. S. Sizov, G. E. Onushkin, et al., in Proceedings of the 13th International Symposium “Nanostructures: Physics and Technology,” St. Petersburg, 2005, p. 294.
3. S. O. Usov, A. F. Tsatsul’nikov, V. V. Lundin, et al., Fiz. Tekh. Poluprovodn. 42, 187 (2008) [Semiconductors 42, 188 (2008)].
4. R. W. Martin, P. G. Middleton, K. P. O’Donnell, and W. Van der Stricht, Appl. Phys. Lett. 74, 263 (1999).
5. R. J. Potter and N. Balkan, J. Phys.: Condens. Mater 16, S3387 (2004).