@inproceedings{per1984the,
title={The spherical Bernstein problem in even dimensions and related problems},
author={Per Tomter},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203308062773398},
booktitle={Acta Mathematica},
volume={158},
number={1},
pages={189-212},
year={1984},
}
Per Tomter. The spherical Bernstein problem in even dimensions and related problems. 1984. Vol. 158. In Acta Mathematica. pp.189-212. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203308062773398.