@article{AFM_1976_2_1_a15,
     author = {Sakari Toppila},
     title = {On {Nevanlinna's} characteristic function of entire functions and their derivatives},
     journal = {Annales Fennici Mathematici},
     pages = {131--134},
     publisher = {mathdoc},
     volume = {2},
     number = {1},
     year = {1976},
     doi = {10.5186/aasfm.1977.0326},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.5186/aasfm.1977.0326/}
}