@article{MZ_1931__33_168264,
     author = {E., Hopf},
     title = {Mathematisches zur {Strahlungsgleichgewichtstheorie} der {Fixsternatmosph\"aren}},
     journal = {Mathematische Zeitschrift},
     pages = {109--128},
     publisher = {mathdoc},
     volume = {33},
     year = {1931},
     zbl = {0001.04101},
     url = {http://geodesic.mathdoc.fr/item/MZ_1931__33_168264/}
}