@inproceedings{e.1951über, title={Über den allgemeinen Integralsinus Si ($z, a$)}, author={E. Kreyszig}, url={http://archive.ymsc.tsinghua.edu.cn/pacm_paperurl/20170108203131437789732}, booktitle={Acta Mathematica}, volume={85}, number={1}, pages={117-181}, year={1951}, }