1. Ashtekar, A., Bicak, J., Schmidt, B.G.: Asymptotic structure of symmetry reduced general relativity. Phys.Rev. D55, 669–686 (1997). arXiv:gr-qc/9608042
2. Barnich, G., Compère, G.: Classical central extension for asymptotic symmetries at null infinity in three spacetime dimensions. Class. Q.Grav. 24, F15–F23 (2007). arXiv:gr-qc/0610130
3. Barnich, G., Troessaert, C.: Aspects of the BMS/CFT correspondence. JHEP 1005, 062 (2010). arXiv:1001.1541
4. Barnich, G., Oblak, B.: Notes on the BMS group in three dimensions: I. Induced representations. JHEP 1406, 129 (2014). arXiv:1403.5803
5. Barnich, G., Oblak, B.: Notes on the BMS group in three dimensions: II. Coadjoint representation. JHEP 1503, 033 (2015). arXiv:1502.00010