The cover of TINTAGEL you see here is from the E-Rights/E-Reads edition. It can be purchased in an electronic format (you will need a reader, of which there are many on the market) or in a print-on-demand format. These can be obtained from the sites listed below. Click on the site's name and you will be immediately teleported to that site.
Sometimes
copies of the original 1981 Ace Science Fiction paperback are available
in used condition. The best sources for these are: