@inproceedings{c.1951the,
title={The minimum of a binary quartic form (II)},
author={C. S. Davis},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203131580028733},
booktitle={Acta Mathematica},
volume={85},
number={1},
pages={183-202},
year={1951},
}