@inproceedings{r.1959lebesgue, title={Lebesgue area of maps from Hausdorff spaces}, author={R. F. Williams}, url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203152498574888}, booktitle={Acta Mathematica}, volume={102}, number={1}, pages={33-46}, year={1959}, }