\bib{1966/erdos}
\yr 1966
\mr 35:2836
\by Paul Erd\H os
\by Jack H. van Lint
\paper On the number of positive integers $\le x$ and free of prime factors $>y$
\jour Simon Stevin
\issn 0037--5454
\vol 40
\pages 73--76
\endref