@inproceedings{johan1997clique,
title={Clique is hard to approximate within$n$^{1−ε}},
author={Johan Håstad},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203333170818574},
booktitle={Acta Mathematica},
volume={182},
number={1},
pages={105-142},
year={1997},
}