@inproceedings{anders1977isometric,
title={Isometric embedding of a smooth compact manifold with a metric of low regularity},
author={Anders Källén},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203502177762279},
booktitle={Arkiv for Matematik},
volume={16},
number={1},
pages={29-50},
year={1977},
}
Anders Källén. Isometric embedding of a smooth compact manifold with a metric of low regularity. 1977. Vol. 16. In Arkiv for Matematik. pp.29-50. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203502177762279.