@article{MZ_1972__125_171694,
     author = {Chung-Chun Yang},
     title = {On {Deficiencies} of {Differential} {Polynomials,} {II.}},
     journal = {Mathematische Zeitschrift},
     pages = {107--112},
     publisher = {mathdoc},
     volume = {125},
     year = {1972},
     zbl = {0217.38402},
     url = {http://geodesic.mathdoc.fr/item/MZ_1972__125_171694/}
}