@article{GDZPPN002371243, title = {Almost periodic recurrent motions}, journal = {Mathematische Zeitschrift}, volume = {30}, year = {1929}, pages = {325-331}, zbl = {55.1094.01}, url = {http://dml.mathdoc.fr/item/GDZPPN002371243} }
Franklin, P. Almost periodic recurrent motions. Mathematische Zeitschrift, Tome 30 (1929) pp. 325-331. http://gdmltest.u-ga.fr/item/GDZPPN002371243/