1. Agard, S. Distortion theorems for quasiconformal mappings. Ann. Acad. Sci. Fenn. Ser. A I No. 413 (1968), 12.
2. Anderson, G. D., Vamanamurthy, M. K., and Vuorinen, M. K.Conformal invariants, inequalities, and quasiconformal maps. Canadian Mathematical Society Series of Monographs and Advanced Texts. John Wiley & Sons, Inc., New York, 1997. With 1 IBM-PC floppy disk (3.5 inch; HD), A Wiley-Interscience Publication.
3. Beardon, A. F.The geometry of discrete groups, vol. 91 of Graduate Texts in Mathematics. Springer-Verlag, New York, 1983.
4. Chen, J., Hariri, P., Klén, R., and Vuorinen, M. K. Lipschitz conditions, triangular ratio metric, and quasiconformal mappings. Ann. Acad. Sci. Fenn. Math. 40, 2 (2015), 683–709.
5. Gehring, F. W., and Hag, K.The ubiquitous quasidisk, vol. 184 of Mathematical Surveys and Monographs. American Mathematical Society, Providence, RI, 2012. With contributions by Ole Jacob Broch.