MathSciDoc: An Archive for Mathematician ∫

@inproceedings{cassius1959suboperative,
  title={Suboperative functions and semi-groups of operators},
  author={Cassius Ionescu Tulcea},
  url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203424632794961},
  booktitle={Arkiv for Matematik},
  volume={4},
  number={1},
  pages={55-61},
  year={1959},
}