@article{MOMA_1994__117_3-4_178637,
     author = {M. Ghamsari and R. N\"akki},
     title = {John {Disks} and {Extensions} of {Maps.}},
     journal = {Monatshefte f\"ur Mathematik},
     pages = {63--94},
     publisher = {mathdoc},
     volume = {117},
     number = {3-4},
     year = {1994},
     zbl = {0794.30020},
     url = {http://geodesic.mathdoc.fr/item/MOMA_1994__117_3-4_178637/}
}