@article{10_4171_ggd_58,
     author = {Bruce Hughes},
     title = {Local similarities and the {Haagerup} property (with an appendix by {Daniel} {S.} {Farley)}},
     journal = {Groups, geometry, and dynamics},
     pages = {299--315},
     year = {2009},
     volume = {3},
     number = {2},
     doi = {10.4171/ggd/58},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/58/}
}