Some extremal properties of conformal mappings of a multiply connected domain onto canonical $p$-sheeted surfaces

Some theorems of Kühnau on the mutual position of the boundary components of images of a multiply connected domain under single-sheeted conformal mappings are generalized to $p$-sheeted conformal mappings of a multiply connected domain with given singularities at given points of the domain. Concrete estimates for certain functionals are obtained for an annulus.