@article{10_2140_agt_2003_3_791,
     author = {Tamanoi, Hirotaka},
     title = {Generalized orbifold {Euler} characteristics of symmetric orbifolds and covering spaces},
     journal = {Algebraic and Geometric Topology},
     pages = {791--856},
     year = {2003},
     volume = {3},
     number = {2},
     doi = {10.2140/agt.2003.3.791},
     url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2003.3.791/}
}