Today I discovered that the project vsenauka.ru, where a plethora of popular science books were officially available for free download, has been shut down. After some Googling, I found https://nauchpop.rusneb.ru/ Despite the 404 Not Found preview in FB, it opens successfully for me, and there is that very library. I randomly checked, the books are there, and downloadable.
Hi, I'm Rauf Aliev. 