@article{GDZPPN002058510,
title = {The spherical derivative of integral and meromorphic functions.},
journal = {Commentarii mathematici Helvetici},
volume = {40},
year = {1965},
pages = {117-148},
zbl = {0142.04303},
url = {http://dml.mathdoc.fr/item/GDZPPN002058510}
}
Clunie, J.; Hayman, W.K. The spherical derivative of integral and meromorphic functions.. Commentarii mathematici Helvetici, Tome 40 (1965) pp. 117-148. http://gdmltest.u-ga.fr/item/GDZPPN002058510/