ev., London&#160;: British Standards Institution, 66 p.</li>
<li>Oberg, E., Jones, F.D., Hussain, M., McCauley, C.J., Ryffel, H.H. and Heald, R.M. (2008) <i>Machinery's handbook&#160;: a reference book for the mechanical engineer, designer, manufacturing engineer, draftsman, toolmaker, and machinist</i>, 28th Ed., New York&#160;: Industrial Press, <a href="//en.wikipedia.org/wiki/Special:BookSources/9780831128005" class="internal mw-magiclink-isbn">ISBN 978-0-8311-2800-5</a>, p.&#160;1858–1860</li>
<li>Wo