@article{00733117, title = {Existence of conjugate points for second-order linear differential equations.}, journal = {Georgian Mathematical Journal}, volume = {2}, year = {1995}, pages = {93-98}, doi = {10.1007/BF02257736}, zbl = {0820.34018}, language = {en}, url = {http://dml.mathdoc.fr/item/00733117} }
Lomtatidze, A. Existence of conjugate points for second-order linear differential equations.. Georgian Mathematical Journal, Tome 2 (1995) pp. 93-98. doi : 10.1007/BF02257736. http://gdmltest.u-ga.fr/item/00733117/