1. M. A. Lavrent’ev, “On the theory of conformal mappings,” Trudy Fiz.-Mat. Inst. AN SSSR, 5, 159–245 (1934).
2. G. M. Goluzin, Geometric Theory of Functions of Complex Variable [in Russian], Nauka, Moscow (1966).
3. J. A. Jenkins, Univalent Functions and Conformal Mappings, Springer, Berlin (1958).
4. W. K. Hayman, Multivalent Functions, Cambridge Univ. Press, Cambridge (1994).
5. V. N. Dubinin, “On the product of inner radii of “partially nonoverlapping” domains,” in: Problems of the Metric Theory of Mappings and Its Applications [in Russian], Naukova Dumka, Kiev (1978), pp. 24–31.