Skip to main content


Indexing, archiving and access to data

Table of contents

Find out more about how we index and archive content, what's our access to data policy as well as useful resources on connecting through our API, the article metrics that we use and more:


Back to top

What is the BioMed Central API?
Our public API is a RESTful API for retrieving open access content published by BioMed Central. Resources are represented in JSON and Prism Aggregate (PAM) formats.

How do I request a BioMed Central API key?
You can request a free API key from the Springer developer site.

Are there any examples of metadata responses from the BioMed Central API?
Example metadata responses are given in the API documentation on the Springer developer site.

How do I use the API RESTful operations?
Further information on using our RESTful API is available on the Springer developer site.

What is the recommended usage of the BioMed Central API?
Our content is licensed using a Creative Commons license (CC-By 4.0) and waiver (CC0 for data). Use of BioMed Central content harvested via the API is covered by our License Agreement.

Article Metrics

Back to top

What are article metrics?

Article metrics provide information on the usage and dissemination of published articles. Examples include:

  • Article accesses
  • Citations
  • Bookmarking/rating/discussion via bibliographic tools/sites such as Papers
  • Social media sharing, such as Facebook, Twitter

Article metrics are provided for all articles published by BioMed Central, to help readers assess the importance and impact of these articles.

What article metrics does BioMed Central provide?

The following metrics are currently available:

  • Access counts – the number of times an article has been accessed on BioMed Central and SpringerLink. Our access counts are COUNTER-compliant. More information
  • Citation counts – our citations database is updated in real time. New citations are added as soon as they become available in the CrossRef database. More information
  • – tracks the discussion and dissemination of articles following their publication. It aggregates the mentions on Twitter and social media sites, and coverage in online reference managers, mainstream news sources and blogs, to present an overview of the interest a published article is receiving online. More information

How does BioMed Central ensure article metrics are reliable?

We monitor and filter article access data to remove 'suspicious' accesses that may distort access statistics. Our access counts are COUNTER-compliant. More information

BioMed Central deposits the articles that it publishes in multiple digital archives around the world to guarantee long-term digital preservation.

These archives include:

INIST (France)
Koninklijke Bibliotheek (The Netherlands)
PubMed Central (United States)
PubMed Central Canada
Europe PubMed Central

BioMed Central makes article metadata available in compliance with Open Archives Initiative protocols, enabling automated 'harvesting' of our research articles for inclusion in any other digital archives. We support non-exclusive digital archiving of research articles by as many international archives as possible, to ensure the security and permanent accessibility of that research.

BioMed Central is a participant in the LOCKSS (Lots of Copies Keep Stuff Safe) initiative. LOCKSS will enable any library to maintain their own archive of content from BioMed Central and other publishers, with minimal technical effort and using cheaply available hardware.

To facilitate data mining research, the full-text XML of all BioMed Central open access research articles is available for ftp download as a ZIP archive. See our data mining research page for more details.


Back to top

Improved equation display for our articles is made possible by using MathJax, an open source JavaScript display engine for mathematics that works in all modern browsers. Because it is JavaScript driven, it does not require the reader to download and install any plugin.

MathJax uses the MathML or TeX stored within the XML of the article and uses modern CSS and web fonts instead of images so that equations scale with the surrounding text at all zoom levels. If MathML or TeX is available, MathJax will be used to render the math by default.

Scaling the page when equations are delivered as graphics causes pixelation and the image becomes difficult to read. This image shows the normal and zoomed view of an equation displayed as a graphic.

Scaling with MathJax enabled, however, allows for all math to scale at the same zoom rate as the text. The image below shows a MathJax rendered equation at standard and zoomed view (please note, this is actually a screenshot, and is therefore an image).

The reader has the option to turn MathJax off or on using the toggle switch.

Other benefits of using MathJax include:

Copy and paste - lets readers copy equations from articles into Word and LaTeX documents, science blogs, research wikis, calculation software such as Maple, Mathematica and more.
Accessibility - compatible with screenreaders used by people with vision disabilities, and the Zoom feature allows all readers to see small details such as scripts, primes and hats. MathJax is supported in most modern browsers, including Chrome, Firefox and Safari.

If you would prefer to view our site without using MathJax, you can disable it by:

1 - unticking the MathJax box and the page will refresh to show graphics instead of the MathML

2 - right clicking an equation to manually select HTML-CSS as the renderer