1. V. L. Berezinskii, “Destruction of the long-range order in one-dimensional and two-dimensional systems with a continuous symmetry group. I. Classical systems,” Zh. Eksp. Teor. Fiz. 59 (3), 907–920 (1970).
2. J. M. Kosterlitz and D. J. Thouless, “Ordering, metastability and phase transition in two-dimensional systems,” J. Phys. C 6 (7), 1181 (1973).
3. B. I. Halperin and D. R. Nelson, “Dislocation mediated melting in two dimensions,” Phys. Rev. B 19 (5), 2457 (1979).
4. V. N. Ryzhov, E. E. Tareeva, Yu. D. Fomin, and E. N. Tsiok, “Berezinskii–Kosterlitz–Taules transition and two-dimensional melting,” Usp. Fiz. Nauk 187 (9), 921–951 (2017).
5. N. Rivier, “Disclination lines in glasses,” Phil. Mag. A 10, 859 (1979).