What Are the Tools Helpful to Write PDF Books?

What are the tools helpful to write PDF books?

You can’t other than by scanning the book, borrowed from a library, and making a PDF copy yourself. That word ‘any’ in your question really makes things difficult. You shouldn’t because PDF is not a format designed for reading onscreen. It’s a format designed for printing. It makes terrible files for reading on an e-reader because the text doesn’t flow when you enlarge it. Instead you need to do a lot of page scrolling. The best ebook formats are EPUB, MOBI or AZW3. PDF files are often available at pirate websites and frequently infected with malware. You may also be breaking the law if you download them. You may also be stealing from the author. You don’t need to because there are millions of free ebooks available, without breaching copyright, already at ebook retailers and other organizations in multiple formats. See this post.