8 As the full text for research papers is typically only available in PDF format (sometimes also in HTML and/or XML), it is generally hard to convert to text format.
we focus on publications by just a few well-known publishers, which cover a sizable proportion of the research papers discussed in Science Daily, and for which we developed parsers: American Association for the Advancement of Science (AAAS), Elsevier, Public Library of Science (PLOS), Proceedings of the National Academy of Sciences (PNAS), Springer, and Wiley.