@article{10_4171_emss_60,
     author = {Jun Hu},
     title = {Characterizations of circle homeomorphisms of different regularities in the universal {Teichm\"uller} space},
     journal = {EMS surveys in mathematical sciences},
     pages = {321--353},
     year = {2022},
     volume = {9},
     number = {2},
     doi = {10.4171/emss/60},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/emss/60/}
}