Interval oscillation criteria for matrix differential systems with damping

This paper concerns the oscillation of solutions to Leighton type for the matrix differential system with damping:(P(t)Y′)′+R(t)Y′+Q(t)Y=0,under the hypothesis: P(t)=P∗(t)>0,Q(t)=Q∗(t) and R(t)=R∗(t) are n×n matrices of real valued continuous functions on the interval [t0,∞).