@article{GDZPPN00228863X, title = {On the Second Order Homogeneous Quadratic Differential Equation.}, journal = {Mathematische Annalen}, volume = {141}, year = {1960}, pages = {87-98}, zbl = {0106.05801}, url = {http://dml.mathdoc.fr/item/GDZPPN00228863X} }
CHALKLEY, R. On the Second Order Homogeneous Quadratic Differential Equation.. Mathematische Annalen, Tome 141 (1960) pp. 87-98. http://gdmltest.u-ga.fr/item/GDZPPN00228863X/