@article{01310485,
title = {Oscillation and nonoscillation criteria for two-dimensional systems of first-order linear ordinary differential equations.},
journal = {Georgian Mathematical Journal},
volume = {6},
year = {1999},
pages = {285-298},
doi = {10.1023/A:1022187214750},
zbl = {0930.34025},
language = {en},
url = {http://dml.mathdoc.fr/item/01310485}
}
Lomtatidze, A.; Partsvania, N. Oscillation and nonoscillation criteria for two-dimensional systems of first-order linear ordinary differential equations.. Georgian Mathematical Journal, Tome 6 (1999) pp. 285-298. doi : 10.1023/A:1022187214750. http://gdmltest.u-ga.fr/item/01310485/