Shao 邵, Y. et al. (n.d.). 19F NMR Study of the Bilayer Iron-Based Superconductor KCa2Fe4As4F2**Supported by the National Key Research and Development Program of China under Grant No 2017YFA0302901, the National Basic Research Program of China under Grant No 2015CB921304, the National Science Foundation of China under Grant Nos 11674375 and 11634015, and the Strategic Priority Research Program and Key Research Program of Frontier Sciences of the Chinese Academy of Sciences under Grant No XDB07020200.. Chinese physics letters. p. . [Online].