Oscillation of First Order Delay Differential Equations1

Some new oscillation criteria for the first-order delay differential equation xX t. qp t.x t t..s0, tGt0 , t t. -t are established in the case where t 1 t 1 Hp s. dsG and limHp s. dss . t t. e tª` t t. e An open problem by A. Elbert and I. P. Stavroulakis 1995, Proc. Amer. Math. Soc. 123, 1503]1510. is solved.