ILLUSTRATION BY THE PROJECT TWINS F access a paywalled paper throughaccess apaywalled institu their up insearches. times, researchers Other can public repositories, but are those hard to pull many authors make papers their available on access publications the need. For they example, and C. L. Giles total of 114 million documents (M.Khabsa available online — roughly 27 million of a guage scholarly documents are freely quarter of web-accessible English-lan a paywall. sometimes, key reference the is hidden behind exactly what find first time, need they but they BY DALMEET SINGHCHAWLA At that point, scientists can mine Twitter the to access it using a different network at home. tions, but themselves find blocked when trying But some researchers it find challenging to According to one analysis, about one- frustratingly hit or miss: sometimes, resources, literature searches can seem or researchers with limited library PLoS ONE 9, e93949; 2014). e93949; 2014). A collection ofweb-browser plug-ins ismaking NEED APAPER? GET APLUG-IN the scholarly literature more discoverable. ©

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- - M a c VPN connections, which can make it difficult able. Some websites and networks block also she that finds connections the unreli can be through private its virtual network (VPN), versity provides access to resources library pus, it is adifferent story. Although uni the she’s on site at Riverside the campus. cam Off catalogue — some 53,000journals — when University of California system’s entire digital Marine biologist Holly Bik has access to the I CAN HAZSCIENCE? through other routes. papers that are inaccessible or hard to find and retrieve open-accesstify copies of research into an overlapping of set data sources to iden dotools more all or less same the thing: tap Button, Scholar and Lazy Kopernio. These to tools such as Unpaywall, Access Open Sci-Hub.service some opt for “pirate self-styled the website” hive-mind using hashtag. #icanhazpdf the And m i l l Increasingly, however, scientists are turning a n

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A 16 NOVEMBER 2017 | VOL 2017 | NATURE 551 | NOVEMBER 16 |399 l l r i g - - - - h t s r e London’s website inMay. publishedan interview on Imperial College Kopernio co-founder Peter Vincent said in represents “a fundamental to barrier progress”, repositories and preprint servers. through open-access journals, institutional to papers the that are freely available online makers. Many of individuals these are limited research periphery,­ such policy as science access kindof to those things.” says. “In day this and age, it’s important to have literature atreasure can be trove of ideas,” Bik lot of researchers tell you will that older this articles that date for back decades, instance. “A a real limitation for to people need find who include only asubset of volumes. This can pose connection you’re when off-campus.” “You’re of kind at mercy of the your Internet to access literature on while road, the Bik says. s e r Kopernio, web-browser afree plug-in The lack of access much to so research So, too, must some people work who on the Even on campus, collections library often v e d .

TOOLBOX

that aims to reduce the search for accessi- Priem and Heather Piwowar, who co-founded ble copies of paywalled papers to a single click, the non-profit firm Impactstory in Vancouver, offers one possible solution. When users land Canada. According to a study published in on a journal article web page for which a copy August and co-authored by the pair, Unpaywall is legally available from open-access publish- can find legal and free copies of the papers ers, preprint archives or a user’s own library that its users land on almost half the time (H. subscription, the plug-in overlays a bar across Piwowar et al. PeerJ Preprints 5, e3119v1; 2017). the top of the page. Clicking a button within If a paper is available, Unpaywall’s grey ‘lock’ that bar brings up the desired PDF. The tool icon turns green and ‘unlocks’. Activating the finds PDFs for about 80% of papers, according ‘OA Nerd Mode’ option colour-codes the to Kopernio co-founder Ben Kaube, a physics unlock sign gold, green or bronze depending doctoral candidate at Imperial. on which open-access subcategory the paper Launched in April as Canary Haz, a play on falls under. (Gold refers to papers published in #icanhazpdf, Kopernio allows users to register open-access journals; green content is published their university log-in credentials, provid- in subscription journals ing those working off-campus with access to “My rate in but archived in an open library resources, even without a VPN. accessing repository; bronze indi- “There is nothing more frustrating than paywalled cates studies that are free trying to do work off campus and coming papers has to read on the current up against paywall after paywall on sites you probably page, but published in a are used to having unfettered access to,” says increased by toll-access journal.) Barney Walker, who is working towards a 50%.” Other options include PhD in synthetic biology at Imperial and is a Open Access Button, in regular user of Kopernio. Even when institu- which users can e-mail tions subscribe to content, he notes, navigat- authors through the click of a button when the ing some publisher sites can be difficult. Papers program can’t find a copy of the paper (or the can be blocked or difficult to load, requiring data set underlying it), and Lazy Scholar, which repeated log-ins, particularly when working provides users with metrics such as the journal off-campus. “Kopernio takes care of that for impact factor and suggests related papers for you, giving you access with a single click to additional reading. Both tools launched in 2013. many different publishers.” These tools largely overlap in the data Vincent says that the plug-in has 3,000 users sources they use, and therefore, the papers across 350 institutions. Although it is still in they can access. These include PubMed Cen- the early stages of development, it already tral, Europe PMC, Google Scholar and the supports more than 20,000 journals and 1,000 Bielefeld Academic Search Engine, a database libraries, with more being added every week. of more than 100 million documents from A ‘locker’ feature allows Kopernio to store 5,000 or so sources. previously accessed papers for future requests What distinguishes these tools from sites by the same user. The tool has also been inte- such as Sci-Hub is that their developers say grated with Google Scholar and PubMed, and that they retrieve only legally available articles. displays a button for each search result for But some publishers still have concerns. Glenn which it can find a PDF. A premium version Ruskin, a spokesperson for the American of Kopernio, which will charge users for fea- Chemical Society (ACS) in Washington DC, tures such as Dropbox integration and private which publishes several pay-to-read journals cloud-based lockers, will launch later this year, singles out Unpaywall, and says that it “must Kaube says. take proper care to direct its users to content- sharing sites that respect the intellectual prop- AN EXPANDING TOOLBOX erty of rightsholders”. In response, Priem says Kopernio is not the first such tool. A popular that he has already tweaked the tool to exclude alternative is Unpaywall, which has more than sources flagged by publishers, and welcomes 100,000 active users worldwide and 75,000 pointers to any other such sites. queries per day. One of those users is Bik, who Other publishers, too, including Springer says that the software “definitely lowers the Nature, which publishes Nature, say that they activation energy required to quickly down- are working to help scientists to access and load a paper”. Another is Stephanie Zihms, share their journal articles through the devel- who studies energy and geoscience at Heriot- opment of their own software. (Nature’s news Watt University in Edinburgh, UK. “My rate team is editorially independent of its publisher.) in accessing paywalled papers has probably Certainly, scientists say that they need increased by 50% or so,” she says. such tools. As Éric Archambault, chief execu- Similarly to Kopernio, Unpaywall is a tive of Science-Metrix in Montreal, Canada, browser extension that simplifies the search puts it, scientists “shouldn’t be spending for open-access PDFs. The tool gets much of hours finding papers”, but “spending hours its data from a database called oaDOI, which reading them”. ■ indexes 90 million papers that have been assigned digital object identifiers (DOIs). Both Dalmeet Singh Chawla is a science journalist Unpaywall and oaDOI were created by Jason in London.

©2017 Ma400c mill a|n PNATUREublishers Li m|i tVOLed, pa r551t of S p|ri n16ge rNOVEMBERNature. All ri ghts 2017reserve |d. CORRECTED 18 DECEMBER 2017 ©2017 Mac millan Publishers Li mited, part of Spri nger Nature. All ri ghts reserved.

CLARIFICATION The Toolbox ‘Need a paper? Get a plug-in’ (Nature 551, 399–400; 2017) stated that Éric Archambault is an independent bibliometrician. He is actually chief executive of Science-Metrix in Montreal, Canada.

©2017 Mac millan Publishers Li mited, part of Spri nger Nature. All ri ghts reserved. ©2017 Mac millan Publishers Li mited, part of Spri nger Nature. All ri ghts reserved.