Superconducting gap symmetry of Ba0.6K0.4Fe2As2 studied by angle-resolved photoemission spectroscopyK. Nakayama, T. Sato, P. Richard, Y.-M. Xu, Y. Sekiba, S. Souma, G. F. Chen, J. L. Luo, N. L. Wang, H. Ding and T. TakahashiEPL, 85 6 (2009) 67002DOI: https://doi.org/10.1209/0295-5075/85/67002