1. Gary, J.D.: On the supremum of the counting function for the $$a$$-values of a meromorphic function. Ph.D. Thesis, University of Illinois at Urbana–Champaign, ProQuest LLC, Ann Arbor, MI, 99 pp (1984)
2. Hayman, W.K.: Meromorphic Functions. Oxford University Press, Oxford (1964)
3. Hayman, W.K., Stewart, F.M.: Real inequalities with applications to function theory. Proc. Camb. Philos. Soc. 50, 250–260 (1954)
4. Miles, J.: Bounds on the ratio $$n(r, a)/S(r)$$ for meromorphic functions. Trans. Am. Math. Soc. 162, 383–393 (1971)
5. Miles, J.: On a theorem of Hayman and Stewart. Complex Var. Theory Appl. 37(1–4), 425–455 (1998)