search network

10 free tools for your literature search

Do you need some freely accessible tools for searching through scientific research?

These resources are passed on from Dr Anna Clemens, who learned about them in a workshop in late 2020 and then investigated further to discover some more. They do not require subscriptions or paid licences. As Clemens states, “closed publishing also makes it hard for persons not affiliated with research institutes, such as the public, to learn about scientific discoveries.”

While open access publishing is gaining in popularity, it is not always clear what open access actually means. UNESCO recently published a set of information modules for researchers and library schools as part of its strategic framework on open access.

What open science tools can support you to review or search through the literature?
What can help you find relevant open access versions of papers and save citations? The information below comes substantially from Anna Clemens’ descriptions for each tool.


ScienceOpen includes a search platform for scientific articles. While company owned, this platform is freely accessible and the design is attractive and functional. Search results are clearly labelled for type of publication, number of citations, altmetric scores etc. and allow for filtering. You can also find the access citation metrics. These show the publications which have cited a certain paper.


Microsoft Academic is a public search engine which has been around for some time. Instead of keyword matching, it uses semantic technologies, which is an interesting approach although it does not reveal as much information about the publications as ScienceOpen.

Read is available as an app or in a browser window and creates a personalised daily feed with new papers on research topics or from journals of your choice. You can find openly accessible versions of an article, or if your institution has journal subscriptions, you can also link them to your Read profile. Read has been created by QxMD.


Citation Gecko is an open source web app that can help you with your literature review. First you upload about 5-6 “seed papers”. The program then extracts all references in and to these papers and creates a visual citation network. The nodes have different colours and sizes to show whether the papers are citing a seed paper or are cited by it and how many, respectively. By investigating the network, you can discover new papers that may be relevant for your literature search. You can also increase your network by including more seed papers which you select for particular purposes.

The underlying citation data that Citation Gecko uses is provided by Crossref, Microsoft Academic (see above) and Open Citations.


Local Citation Network operates similarly to Citation Gecko to generate a network of new articles and publications on your research topic. It works best if you feed it with a larger library of seed papers than required for Citation Gecko and is recommended for the end of the literature review process to find papers you might have missed or which were not available earlier.


As an alternative to Citation Gecko and Local Citation Network, one of Anna Clemen’s readers recommended ResearchRabbit. You can build your own literature network for free with this. ResearchRabbit lets you add labels to the entries in your network, download PDFs of papers and sign up for email alerts for new papers related to your research topic. Instead of a tool to use only once during your literature search, ResearchRabbit seems to work more like a private scientific library storing (and connecting) papers in your field.


When you enter the DOI, link or citation of a paper, Open Access Button shows it if freely accessible anywhere. This tool searches preprint servers, authors’ personal pages, open access journals and other aggregators such as CORE which is the COnnecting REpositories service based at The Open University in the UK, the EU-funded OPenAire infrastructure, and Share which is a US community initiative. If the article you are looking for is not freely available, Open Access Button asks the author to share it to a repository. You can enter your email address to be notified once it has become available. Open Access Button is also available as browser plugin, which means that a button appears next to an article when a free version is available. The tool is funded by non-profit foundations.

Unpaywall is similar to the Open Access Button but only available as browser plugin. If the article you are looking at is behind a paywall but freely accessible somewhere else, a green button appears on the right side of the article. Unpaywall is run by the non-profit organisation called Our Research which has created quite a few open science tools.

The underlying citation data that Citation Gecko uses is provided by Crossref, Microsoft Academic (see above) and Open Citations.

Another browser extension that lets you access papers for free if available is EndNote Click (formerly Kopernio). As the reference manager, EndNote Click is part of the research analytics company Clarivate and they make the claim that it is   
faster than other plugins as it bypasses some redirects and verification steps. One advantage of EndNote Click is the side bar that appears when opening a paper through the plugin. It lets you, for example, save citations quickly, avoiding time-consuming searches on publishers’ websites.

CiteAs is a convenient tool to obtain the correct citation for any publication, preprint, software or dataset in one click. Funded by the Alfred P. Sloan Foundation, CiteAs is another tool which Our Research partly operates.

So here you have 10 tools to explore. If you are using any of them already, please let me know what you think of them. If there are others you would like to share, I would love to receive an email.