@article{GDZPPN00240818X, title = {The Boundary Behaviour of Derivatives of Univalent Functions.}, journal = {Mathematische Zeitschrift}, volume = {121}, year = {1971}, pages = {115-120}, zbl = {0196.09201}, url = {http://dml.mathdoc.fr/item/GDZPPN00240818X} }
Lohwater, A.J. The Boundary Behaviour of Derivatives of Univalent Functions.. Mathematische Zeitschrift, Tome 121 (1971) pp. 115-120. http://gdmltest.u-ga.fr/item/GDZPPN00240818X/