\bib{1988/young}
\yr 1988
\mr 89b:11012
\by Jeff Young
\by Duncan A. Buell
\paper The twentieth Fermat number is composite
\jour Mathematics of Computation
\issn 0025--5718
\vol 50
\pages 261--263
\url http://cr.yp.to/\allowbreak bib/\allowbreak entries.html#\allowbreak 1988/\allowbreak young
\endref