@article{2224,
author = {Taam, Choy-Tak},
title = {Non-oscillation and comparison theorems of linear differential equations with complex-valued coefficients},
journal = {Portugaliae mathematica},
volume = {12},
year = {1953},
pages = {57-72},
zbl = {0053.38402},
mrnumber = {0054115},
language = {en},
url = {http://dml.mathdoc.fr/item/2224}
}
Taam, Choy-Tak. Non-oscillation and comparison theorems of linear differential equations with complex-valued coefficients. Portugaliae mathematica, Tome 12 (1953) pp. 57-72. http://gdmltest.u-ga.fr/item/2224/