Books contain the most carefully crafted and edited text that we have – truly the richest source of information in the world – and yet all that information remains unlinkable. Google works as well as it does because people find interesting information on the web and link to it; Google then prioritises pages that attract a disproportionate number of inbound links. But if you find a fascinating passage in a novel or a book of history, there is no standardised way to link to it, which means that the rest of the web cannot benefit from your discovery.Fortunately, a solution to this problem exists, one that merely involves a commitment to use technology that already exists. Call it the mirror web. If you create digital information in any form, make a parallel version of that information that lives on the web. A magazine publisher creating an iPad app should ensure that each article has clear links to a mirror version of each article on the web. Then, if anyone wants to cite, tweet, blog or e-mail a reference to that article, it is always one tap away. The web version can be behind a pay wall or some other kind of barrier if the publisher chooses; what matters is that there is an address you can point to.