Anisotropic spin fluctuations and multiple superconducting gaps in hole-doped Ba0.72K0.28Fe2As2: NMR in a single crystalK. Matano, Z. Li, G. L. Sun, D. L. Sun, C. T. Lin, M. Ichioka and Guo-qing ZhengEPL, 87 2 (2009) 27012DOI: https://doi.org/10.1209/0295-5075/87/27012