MathSciDoc: An Archive for Mathematician ∫

@inproceedings{b.1989degenerations,
  title={Degenerations of minimal ruled surfaces},
  author={B. Crauder},
  url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203533114187540},
  booktitle={Arkiv for Matematik},
  volume={28},
  number={1},
  pages={259-271},
  year={1989},
}