From the Description: "The dataset contains all COVID-19 and coronavirus-related research (e.g. SARS [severe acute respiratory syndrome], MERS [Middle East respiratory syndrome], etc.) from the following sources:  PubMed's PMC [PubMed Central] open access corpus using this query (COVID-19 and coronavirus research);  Additional COVID-19 research articles from a corpus maintained by the WHO [World Health Organization]; [and 3] bioRxiv and medRxiv pre-prints using the same query as PMC (COVID-19 and coronavirus research). We also provide a comprehensive metadata file of 29,000 coronavirus and COVID-19 research articles with links to PubMed, Microsoft Academic and the WHO COVID-19 database of publications (includes articles without open access full text)."
Semantic Scholar: https://www.semanticscholar.org/