@article{JRAM_1969__237_150941,
     author = {Ulrich Christian},
     title = {Untersuchung einer {Poincar\'eschen} {Reihe.} {II.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {12--25},
     publisher = {mathdoc},
     volume = {237},
     year = {1969},
     zbl = {0176.04202},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1969__237_150941/}
}