@article{AFM_1993_18_1_a2,
     author = {Dariusz Partyka},
     title = {Approximation of the {Hersch-Pfluger} distortion function},
     journal = {Annales Fennici Mathematici},
     pages = {23--29},
     year = {1993},
     volume = {18},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AFM_1993_18_1_a2/}
}