참고문헌
- T. B. Cao and H. X. Yi, On the complex oscillation of higher order linear differential equations with meromorphic coefficients, J. Syst. Sci. Complex. 20 (2007), no. 1, 135. 148 https://doi.org/10.1007/s11424-007-9012-7
- Z. X. Chen and K. H. Shon, On subnormal solutions of second order linear periodic differential equations, Sci. China Ser. A 50 (2007), no. 6, 786.800 https://doi.org/10.1007/s11425-007-0050-3
- Y. M. Chiang and S. A. Gao, On a problem in complex oscillation theory of periodic second order linear differential equations and some related perturbation results, Ann. Acad. Sci. Fenn. Math. 27 (2002), no. 2, 273.290
- G. Gundersen, Estimates for the logarithmic derivative of a meromorphic function, plus similar estimates, J. London Math. Soc. (2) 37 (1988), no. 1, 88.104 https://doi.org/10.1112/jlms/s2-37.121.88
- G. Gundersen and E. M. Steinbart, Subnormal solutions of second order linear differential equations with periodic coefficients, Results Math. 25 (1994), no. 3-4, 270.289 https://doi.org/10.1007/BF03323411
- G. Jank and L. Volkmann, Einfuhrung in die Theorie der ganzen und Meromorphen Funktionen mit Anwendungen auf Differentialgleichungen, Birkhauser Verlag, Besel, 1985
- L. Kinnunen, Linear differential equations with solutions of finite iterated order, Southeast Asian Bull. Math. 22 (1998), no. 4, 385.405
- I. Laine, Nevanlinna Theory and Complex Differential Equations, de Gruyter Studies in Mathematics, 15. Walter de Gruyter & Co., Berlin, 1993
-
H. Wittich, Subnormale Losungen der Differentialgleichung:
$$w^{\prime\prime}+p(e^{z})w^{\prime}+q(e^{z})w$ =0, Nagoya Math. J. 30 (1967), 29.37 https://doi.org/10.1017/S0027763000012320 - C. C. Yang and H. X. Yi, Uniqueness Theory of Meromorphic Functions, Mathematics and its Applications, 557. Kluwer Academic Publishers Group, Dordrecht, 2003