最近５年間の論文
  1. Homoclinic orbits in generalized Li\'enard systems, J. Math. Anal. Appl. 309 (2005), 211--226.
  2. Growth conditions for oscillation of nonlinear differential equations with $p$-Laplacian (with N. Yamaoka), J. Math. Anal. Appl. 306 (2005), 18--34 (MR2132886).
  3. Oscillation criteria of Kneser-Hille type for second-order differential equations with nonlinear perturbed terms, Rocky Mountain J. Math. 34 (2004), 1519--1537 (MR2095591).
  4. Influence of nonlinear perturbed terms on the oscillation of elliptic equations (with N. Yamaoka), Proc. Amer. Math. Soc. 132 (2004), 2281--2290 (MR2052404).
  5. Oscillation of solutions of second-order nonlinear self-adjoint differential equations (with N. Yamaoka), J. Math. Anal. Appl. 291 (2004), 387--405 (MR2038178).
  6. Phase plane analysis in oscillation theory of nonlinear delay difference equations (with Y. Ono), J. Difference Equ. Appl. 10 (2004), 99--116 (MR2033336).
  7. Global asymptotic stability of nonautonomous systems of Li\'nard type (with Y. Amano), J. Math. Anal. Appl. 289 (2004), 673--690 (MR2026933 (2004j:34114)).
  8. Applications of phase plane analysis of a Li\'enard system to positive solutions of Schr\"{o}dinger equations (with N. Yamaoka), Proc. Amer. Math. Soc. 131 (2003), 501-509.
  9. Decaying positive solutions of quasilinear elliptic equations in exterior domains in $\bf{R}^2$ (with N. Yamaoka), J. Math. Anal. Appl. 275 (2002), 288--311.
  10. Oscillation constant of second order nonlinear self-adjoint differential equations (with K. Kita and N. Yamaoka), Ann. Mat. Pura Appl. (4), 181 (2002), 309-337.
  11. An infinite sequence of nonoscillation theorems for second order nonlinear differential equations of Euler type (with N. Yamaoka), Nonlinear Anal. 50 (2002), 373-388.
  12. On the position of unbounded separatrices for van der Pol's system, Dynamic Systems Appl. 11 (2002), 53-64.
  13. Nonoscillation theorems for a nonlinear self-adjoint differential equation (with N. Yamaoka and Y. Obata), Nonlinear Anal. 47 (2001), 4433-4444.
  14. A nonoscillation theorem for second order nonlinear differential equations with decaying coefficients, Bull. London Math. Soc. 33 (2001), 299-308 (MR 2002a:34048).
  15. Li\'enard dynamics with an open limit orbit, NoDEA Nonlinear Differential Equations Appl. 8 (2001), 83-97 (MR 2002c:34073).
  16. Oscillation criteria for second order nonlinear differential equations of Euler type (with K. Kita), J. Math. Anal. Appl. 253 (2001), 414-439 (MR 2001k:34063).