@article{MZ_1930__32_168232,
     author = {L., Sachs},
     title = {Untersuchung der dynamischen {Stabilit\"at} der {Bewegung} im {Falle} {U=r6}},
     journal = {Mathematische Zeitschrift},
     pages = {376--385},
     publisher = {mathdoc},
     volume = {32},
     year = {1930},
     zbl = {56.1217.03},
     url = {http://geodesic.mathdoc.fr/item/MZ_1930__32_168232/}
}