Bloch's Theorem for Algebroid Multifunctions II
Dominique Guillot, Thomas Ransford · Mathematical Proceedings of the Royal Irish Academy · 2005
Bloch's theorem is extended to multifunctions of the form $F(z) = \{ w \in \mathbb{C}:w^n + a_1 (z)w^{n - 1} + ... + a_{n - 1} (z)w + a_n (z) = 0\} (|z| < 1)$, where a₁(z),...,an(z) are holomorphic functions on the unit disc and $a_1^' (0) = 1$