@article{AFM_2007_32_2_a4,
     author = {X. Wang and M. Huang and S. Ponnusamy and Y. Chu},
     title = {Hyperbolic distance, {\lambda-Apollonian} metric and {John} disks},
     journal = {Annales Fennici Mathematici},
     pages = {371--380},
     publisher = {mathdoc},
     volume = {32},
     number = {2},
     year = {2007},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AFM_2007_32_2_a4/}
}