E-print: http://arxiv.org/abs/1204.0922
E-print: http://arxiv.org/abs/1105.1694
E-print: http://arxiv.org/abs/1106.3016
E-print: http://arxiv.org/PS_cache/arxiv/pdf/1009/1009.2928v1.pdf
E-print: https://arxiv.org/abs/physics/0507073
E-print: http://arxiv.org/abs/cond-mat/0501292
E-print: http://arxiv.org/abs/cond-mat/0403022
E-print: http://arxiv.org/abs/cond-mat/0308570
E-print: http://arxiv.org/abs/cond-mat/0304514
E-print: http://arxiv.org/abs/cond-mat/0303584
E-print: http://arxiv.org/abs/cond-mat/0302095
E-print: https://arxiv.org/abs/cond-mat/0206222
E-print: https://arxiv.org/abs/cond-mat/0204047
E-print: http://arxiv.org/abs/cond-mat/0105076