Duringhis short lifeOswald Teichmuller wrote 34 papers, all reproduced in this volume.

From thePreface: "Teichmuller's most influential paper was called "Extremale quasikonforme Abbildungen und quadratische Differentiale" (No. 20 in this collection). At the time of its appearance several special cases of extremal problems for quasiconformal mappings had already been solved, and Teichmuller was able to draw on a substantial fund of experience. Nevertheless, it was a remarkable feat to extract the common features of all the known examples and formulate a conjecture, now known as...