Blanka
Baculikova
Address. 
Department of Mathematics FEI, Technical
University, B. Nemcovej 
32, 042 00  Kosice,  Slovak Republic
E-mail:  Blanka.Baculikova@tuke.sk
Abstract. 
Our aim in this paper is
to present criteria for oscillation of the nonlinear
differential equation $$
u^{\prime\prime}(t)+p(t)f\big(u(g(t))\big)=0\,.$$  
The obtained oscillatory criteria improve existing ones.
AMSclassification. Primary: 34C10,34K11
Keywords. Oscillatory solution.