@article{10_4153_CMB_1973_002_0,
     author = {Allegretto, W. and Erbe, L.},
     title = {Oscillation {Criteria} for {Matrix} {Differential} {Inequalities(1)}},
     journal = {Canadian mathematical bulletin},
     pages = {5--10},
     year = {1973},
     volume = {16},
     number = {1},
     doi = {10.4153/CMB-1973-002-0},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1973-002-0/}
}