@article{10_4064_ap_29_2_173_187,
     author = {Philip Hartman},
     title = {Logarithmic derivatives of solutions of disconjugate differential equations},
     journal = {Annales Polonici Mathematici},
     pages = {173--187},
     publisher = {mathdoc},
     volume = {29},
     number = {2},
     year = {1974},
     doi = {10.4064/ap-29-2-173-187},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-29-2-173-187/}
}