I wrote a mathematics textbook (high-school level), in PDF format. It is free and I just want it to be as widely-distributed as possible.
Converting it to any other format makes it awful. (It's merely awful when converted to .docx, but completely unusable when in .epub format.)
Many websites (e.g. Smashwords) don't accept PDF though. So I'm wondering if someone could give me a list of sites where I can publish my PDF ebook.