@article{10_2140_agt_2011_11_2437,
     author = {Wu, Jianchun and Zhao, Xuezhi},
     title = {Free degrees of homeomorphisms on compact surfaces},
     journal = {Algebraic and Geometric Topology},
     pages = {2437--2452},
     year = {2011},
     volume = {11},
     number = {4},
     doi = {10.2140/agt.2011.11.2437},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2011.11.2437/}
}