@article{10_2140_agt_2002_2_1119,
     author = {Tuffley, Christopher},
     title = {Finite subset spaces of {S1}},
     journal = {Algebraic and Geometric Topology},
     pages = {1119--1145},
     year = {2002},
     volume = {2},
     number = {2},
     doi = {10.2140/agt.2002.2.1119},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2002.2.1119/}
}