@article{MS2_1994__74_1_167299,
     author = {Shengjian Wu},
     title = {On the {Location} of {Zeros} of {Solutions} of f'' + {A(z)f} = 0 where {A(z)} is {Entire.}},
     journal = {Mathematica Scandinavica},
     pages = {293--312},
     publisher = {mathdoc},
     volume = {74},
     number = {1},
     year = {1994},
     zbl = {0827.34003},
     url = {http://geodesic.mathdoc.fr/item/MS2_1994__74_1_167299/}
}