My BioStor project has reached over 13,000 articles, making it a sizeable respository of open access articles on biodiversity. It's still a tiny fraction of what could be extracted from the Biodiversity Heritage Library (BHL), but perhaps it's worth taking stock of what's there. Coverage One pleasing discovery is that, despite the 1923 cut-off due to U.S. copyright, BHL contains a lot of post-1923 articles.