@article{MAN_1973__200_162365,
     author = {W.N. Everitt and M. Giertz and J. Weidmann},
     title = {Some {Remarks} on a {Separation} and {Limit} - point {Criterion} of {Second-order,} {Ordinary} {Differential} {Expressions.}},
     journal = {Mathematische Annalen},
     pages = {335--346},
     publisher = {mathdoc},
     volume = {200},
     year = {1973},
     zbl = {0235.34045},
     url = {http://geodesic.mathdoc.fr/item/MAN_1973__200_162365/}
}