@article{IM_1984__75_143097,
     author = {W. Sinnott},
     title = {On the ?-invariant of the ?-transform of a rational function.},
     journal = {Inventiones mathematicae},
     pages = {273--282},
     publisher = {mathdoc},
     volume = {75},
     year = {1984},
     zbl = {0531.12004},
     url = {http://geodesic.mathdoc.fr/item/IM_1984__75_143097/}
}