Donal O’regan

Oscillation criteria for nonlinear perturbed dynamic equations of second-order on time scales

Ravi P. Agarwal, S. H. Saker, D. O’Regan, 2006 .

Positive solutions and eigenvalue intervals for nonlinear systems

Meirong Zhang, Jifeng Chu, Jifeng Chu, 2007 .

Oscillation theorems for second-order nonlinear neutral delay dynamic equations on time scales

Ravi P. Agarwal, Samir H. Saker, D. O’Regan, 2008 .