o see P. R. Anderson and D. R. Brill, "Gravitational Geons Revisited" Phys. Rev. D56 (1997) 4824-4833, arXiv:gr-qc/9610074 [77] W. Xu, L. Zhao, and D. Zou, "Three dimensional rotating hairy black holes, asymptotics and thermodynamics" arXiv:1406.7153 [78] E P Wigner, "Die Messung quantenmechanischer O