@article{AFM_2001_26_1_a7,
     author = {Kari Per Hag},
     title = {John disks and the {pre-Schwarzian} derivative},
     journal = {Annales Fennici Mathematici},
     pages = {205--224},
     publisher = {mathdoc},
     volume = {26},
     number = {1},
     year = {2001},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AFM_2001_26_1_a7/}
}