@article{JRAM_1932__168_149824,
     author = {A. Hammerstein},
     title = {\"Uber die {Eigenwerte} gewisser nichtlinearer {Differentialgleichungen.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {37--43},
     year = {1932},
     volume = {168},
     zbl = {58.0468.02},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1932__168_149824/}
}