@article{GDZPPN002061503, title = {A Criterion for a Meromorphic Function to be Normal}, journal = {Commentarii mathematici Helvetici}, volume = {49}, year = {1974}, pages = {492-495}, zbl = {0292.30029}, url = {http://dml.mathdoc.fr/item/GDZPPN002061503} }
Lappan, Peter. A Criterion for a Meromorphic Function to be Normal. Commentarii mathematici Helvetici, Tome 49 (1974) pp. 492-495. http://gdmltest.u-ga.fr/item/GDZPPN002061503/