@article{1955-chowla
,author={Sarvadaman D. Chowla and William E. Briggs}
,ISSN={0002--9939}
,journal={Proceedings of the American Mathematical Society}
,MR={17,127l}
,pages={558--562}
,title={{On the number of positive integers $\le x$ all of whose prime factors are $\le y$}}
,volume={6}
,year={1955}
}