All the students in a course I was teaching apparently were using Chegg for the previous year’s textbook so I decided to use as a supplement (to Strang [which was not the previous year’s book but had all the answers online anyway]) an old Mir publishers book on Diff Eq which I can’t remember exactly how I got (either a bookstore in the French quarter or maybe a library remainder sale).

At any rate it turns out the English printing is so rare not only can it not be found on Libgen - the few copies online are selling for hundreds of dollars (which I certainly would not have paid for it). So not only did I luck into a paper fortune (I suspect this is a rather illiquid market - plus I had to go through and fix a bunch of typos by hand, so much for the Soviet STEM educational complex) the kids _definitely_ couldn’t find this on the Internet.

Did you put it on libgen?

I may soon - there is a book scanner in the med school library and I doubt very much they care about a Soviet copyrighted book (if USSR even asserted such a thing abroad or Russia does now for them).

Russia increasingly does not care about copyright of foreign stuff, so there's that symmetry going too.

This thread is bringing back so many bad memories.