1. A. Eremenko, Rational solutions of first-order differential equations, Ann. Acad. Sci. Fenn. Math. 23 (1998), 181–190.
2. S. Gao, On the number of meromorphic solutions of one class of ordinary differential equations, Act a Math. Sinica 30 (1987), 160–167 (in Chinese).
3. S. Gao, On the number of meromorphic solutions of one class of ordinary differential equations, Kexue Tongbao 31 (1987), 1652–1653.
4. A. Granville and T. J. Tucker, It’s as easy as abc, Notices Amer. Math. Soc. 49 (2002), 1224–1231.
5. G. G. Gundersen, Complex functional equations, in: I. Laine (ed.), Complex Differential and Functional Equations, Mekrijärvi, 2000, Univ. Joensuu Dept. Math. Report Series 5 (2003), 21–50.