\bib{1973/thurber}
\yr 1973
\mr 48:8429
\by Edward G. Thurber
\paper On addition chains $l(mn)\le l(n)-b$ and lower bounds for $c(r)$
\jour Duke Mathematical Journal
\issn 0012--7094
\vol 40
\pages 907--913
\url http://cr.yp.to/\allowbreak bib/\allowbreak entries.html#\allowbreak 1973/\allowbreak thurber
\endref