@inproceedings{johan2011encomplexed,
title={Encomplexed Brown invariant of real algebraic surfaces in ℝ$P$^{3}},
author={Johan Björklund},
url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203636003689048},
booktitle={Arkiv for Matematik},
volume={51},
number={2},
pages={251-267},
year={2011},
}

Johan Björklund. Encomplexed Brown invariant of real algebraic surfaces in ℝ$P$^{3}. 2011. Vol. 51. In Arkiv for Matematik. pp.251-267. http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203636003689048.