The electronic version of my book Linear Algebra Done Right is free until the end of July. This generous gesture by Springer Nature is intended to help out during the coronavirus pandemic. The book can be downloaded at
https://link.springer.com/book/10.1007/978-3-319-11080-6.
https://link.springer.com/content/pdf/10.1007%2F978-3-319-11080-6.pdf