Oscillation criteria for second order differential equations with positive and negative coefficients. - Jelena V. Manojlovic; Yutaka Shoukaku; Tomoyuki Tanigawa; Norio Yoshida (Appl. Math. Comput., 2006)

Oscillation criteria for a class of second-order neutral delay differential equations. - Basak Karpuz; Jelena V. Manojlovic; Özkan Öcalan; Yutaka Shoukaku (Appl. Math. Comput., 2009)

Forced oscillation of certain neutral hyperbolic equations with continuous distributed deviating arguments. - Yutaka Shoukaku (Math. Comput. Model., 2009)

Oscillations of nonlinear hyperbolic equations with functional arguments via Riccati method. - Yutaka Shoukaku; Norio Yoshida (Appl. Math. Comput., 2010)

Forced oscillatory result of hyperbolic equations with continuous distributed deviating arguments. - Yutaka Shoukaku (Appl. Math. Lett., 2011)