foghorn
Valued Senior Member
Ned, I know you like SR and GR. Did you know Bertrand Russell's book is now in public domain from last Jan.For public domain e-books, I have used Project Gutenberg before:
https://www.gutenberg.org/
They usually offer the e-books in a few different formats, some with illustrations, some just text.
The A B C of Relativity by Bertrand Russell
https://www.gutenberg.org/ebooks/67104