@inproceedings{per1967microbundles,
title={Microbundles and$S$-duality},
author={Per Holm},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203212600173039},
booktitle={Acta Mathematica},
volume={118},
number={1},
pages={271-296},
year={1967},
}