1. Frank, G., Weissenborn, G.: Rational deficient functions of meromorphic functions. Bull. Lond. Math. Soc. 18(1), 29–33 (1986)
2. Gol’dberg, A., Ostrovskii, I.: Value distribution of meromorphic functions. Translations of Mathematical Monographs. American Mathematical Society, Providence (2008)
3. Hayman, W.K.: Meromorphic Functions. Oxford Mathematical Monographs. Clarendon Press, Oxford (1964)
4. Ishizaki, K.: Some remarks on results of Mues about deficiency sums of derivatives. Arch. Math. 55, 374–379 (1990)
5. Jiang, Y., Huang, B.: A note on the value distribution of f1(f(k))n. Hiroshima Math. J. 462, 135–147 (2016)