This repository contains code used to extract details of preprints related to COVID-19 and visualize their distribution over time.
With respect to Crossref, all records defined as "posted-content" are harvested using the
function of the rcrossref package, and filtered for partial matches to
keywords relating to COVID-19 ("coronavirus", "covid-19", "sars-cov",
"ncov-2019", "2019-ncov") in either their titles or abstracts. The
properties are then used to match preprints to relevant preprint
repositories. In some cases, multiple Crossref records are registered
for a single preprint (e.g. ChemRxiv registers a new Crossref record for
each new version of a preprint). In these cases, only the earliest
posted version is included in this dataset. Additionally, some preprints
are deposited to multiple preprint repositories - in these cases both
preprint records are included.
With respect to arXiv, records are harvested by searching directly (using the
arxiv_search function of the aRxiv package) for COVID-19 related keywords in titles or abstracts.