@article{MAN_1986__276_164214,
     author = {Ch. Pommerenke},
     title = {On the {Boundary} {Derivative} for {Univalent} {Functions.}},
     journal = {Mathematische Annalen},
     pages = {499--504},
     publisher = {mathdoc},
     volume = {276},
     year = {1986},
     zbl = {0596.30027},
     url = {http://geodesic.mathdoc.fr/item/MAN_1986__276_164214/}
}