Chen, Jiaolong, Parisa Hariri, Riku Klén, and Matti Vuorinen. 2015. “Lipschitz Conditions, Triangular Ratio Metric, and Quasiconformal Maps”. Annales Fennici Mathematici 40 (2):683-709. https://doi.org/10.5186/aasfm.2015.4039.