Remarks on a paper of C. Huang

We prove oscillation and nonoscillation theorems for the second order linear differential equation (E) <f>y″+q(t)y=0</f>, where <f>q(t)&ges;0</f> and locally integrable on <f>[t&ast;,∞).</f> These results are extensions of earlier results of Huang [J. Math. Anal. Appl. 210 (1997) 712–723]. Furthermore, we show that the oscillation criterion established for Eq. (E) can be extended to the delayed differential equation <f>y″+q(t)y(σ(t))=0</f>, where <f>σ(t)&les;t</f> and <f>limt→∞σ(t)=∞.</f> [Copyright &y& Elsevier]