1. Kimura, T.: On the iteration of analytic functions. Funkcial. Ekvac., 14, 197–238 (1971)
2. Shimomura, S.: Entire solutions of a polynomial difference equation. J. Fac. Sci. Univ. Tokyo Sect. IA Math., 28, 253–266 (1981)
3. Yanagihara, N.: Meromorphic solutions of some difference equations. Funkcial. Ekvac., 23, 309–326 (1980)
4. Hayman, W. K.: Meromorphic Functions, Clarendon Press, Oxford, 1964
5. Yang, L.: Value Distribution Theory and New Research (in Chinese), Science Press, Beijing, 1982