The articles in this volume are for the most part research articles related mainly to the theory of quasiconformal and quasiregular mappings, Riemann surfaces and potential theory. They have resulted from talks delivered at the 13th Nevanlinna Colloquium, which was also a celebration of the 80th birthday of Lars V. Ahlfors: hence many articles in this volume reflect his mathematical interests.

Inequalities for the extremal distortion function.- Complete Klein coverings of Klein surfaces of characteristic 0. I.- Quasiconformal extension of plane quasimöbius embeddings.- Some integral conditions involving the spherical derivative.- The dianalytic morphisms of the Klein bottles.- Remarks on Sobolev imbedding inequalities.- A generalization of the Teichmüller theorem.- Unbounded Feynman integrable functionals defined in terms of analytic functions.- Dynamics of maps with constant Schwarzian derivative.- Rational Riemann maps.- A characterization of quasiconformal mappings by the behaviour of a function of three points.- On a class of univalent functions.- Integral means of ?-strongly starlike functions.- On p-adic Nevanlinna theory.- Ahlfors' theorem on asymptotic values and some developments from it.- Regular b-groups and repeated Dehn twists.- Metric boundary conditions for plane domains.- Compactifications of harmonic spaces and Hunt processes.- Convex functions and the Nehari univalence criterion.- A Green formula with multiplicities.- A riemannian metric invariant under Möbius transformations in ?n.- Deformation of one-dimensional quasisymmetric embeddings.- On the exponent of convergence for infinitely generated Fuchsian groups.- The relation between the bounded point derivation and the fine derivation.- Moduli of continuity and a Hardy-Littlewood theorem.- A short proof of a theorem of Ahlfors.- Remarks on the Picard theorem.- Nonequidimensional value distribution theory.- Poincaré domains in the plane.- Concerning the Gross star theorem.- On harmonic majorization.- Homeomorphic conjugates of Fuchsian groups: An outline.- Konforme und quasikonforme Abbildungen und das Krümmungsverhalten von Kurvenscharen.- Carleson measure and BMO interpolation.-Extending plurisubharmonic and holomorphic functions.