@article{10_4064_aa129_4_8,
     author = {Hao Pan and Zhi-Wei Sun},
     title = {A characterization of covering equivalence},
     journal = {Acta Arithmetica},
     pages = {397--402},
     publisher = {mathdoc},
     volume = {129},
     number = {4},
     year = {2007},
     doi = {10.4064/aa129-4-8},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/aa129-4-8/}
}