Degeneration of quasicircles: Inner and outer radii of Teichmüller spaces. Velling, John A. (1993) Annales Academiae Scientiarum Fennicae. Series A I. Mathematica
Diameter problems for univalent functions with quasiconformal extension. Deiermann, Paul (1993) International Journal of Mathematics and Mathematical Sciences
Dirichlet's Principle, Uniqueness of Harmonic Maps and Extremal QC Mappings Miodrag Mateljević (2004) Zbornik Radova