Spin-singlet superconductivity with multiple gaps in PrFeAsO0.89F0.11K. Matano, Z. A. Ren, X. L. Dong, L. L. Sun, Z. X. Zhao and Guo-qing ZhengEPL, 83 5 (2008) 57001DOI: https://doi.org/10.1209/0295-5075/83/57001