@article{SM_1968_4_1_a3,
     author = {A. Yu. Levin},
     title = {Behavior of the solutions of the equation $\ddot x+p(t)\dot x+q(t)x=0$ in the nonoscillatory case},
     journal = {Sbornik. Mathematics},
     pages = {33--55},
     year = {1968},
     volume = {4},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1968_4_1_a3/}
}