Special Corona sites with free literature - e-books, articles and videos - on Corona and the COVID-19 virus have been established by several publishers.
Here is a list of selected links:
SpringerNature Oxford University Press Karger Taylor & Francis Emerald McGrawHill Medicine JAMA IEEE free online courses Royal Society IOP Publishing Cambridge University Press API Publishing [02-04-2020] SIAM [03-04-2020] GeoScienceWorld [03-04-2020] Proquest database [06-04-2020] The Institution of Engineering and Technology, IET [14-04-2020]