1. A. Einstein, Sitzungsber. Preuss. Akad. Wiss., Phys.-Math. Kl., 261 (1924)
2. A. Einstein, Sitzungsber. Preuss. Akad. Wiss., Phys.-Math. Kl., 3 (1925)
3. N.N. Bogoliubov, J. Phys. USSR 11, 23 (1947)
4. O. Penrose, L. Onsager, Phys. Rev. 104, 576 (1956)
5. A. Griffin, A brief history of our understanding of BEC: From Bose to Beliaev, in Bose–Einstein Condensation in Atomic Gases, ed. by M. Inguscio, S. Stringari, C.E. Wieman (IOS Press, Amsterdam, 1999), pp. 1–13. arXiv:cond-mat/9901123