@article{JGG_2004_8_2_JGG_2004_8_2_a9,
     author = {P. Yiu },
     title = {Generalized {Apollonian} {Circles}},
     journal = {Journal for geometry and graphics},
     pages = {225--23},
     publisher = {mathdoc},
     volume = {8},
     number = {2},
     year = {2004},
     url = {http://geodesic.mathdoc.fr/item/JGG_2004_8_2_JGG_2004_8_2_a9/}
}