- Steve Canada's collection of books on the topic. Several selections to choose from covering UFOs and other things of this nature as well as working theories. Also lecture and interview information.
- Crop circle symbols can be easily interpreted using Biblical symbols, the book of Revelation in particular. A few chapters of the book are free on the web site.
- Web site of crop circle photographer Steve Alexander and writer Karen Douglas. Online image library, online shop of stock photos and a selection of articles.
- About a swirled circle apprently left by a UFO in Tully, Australia back in 1966. Circlemaker Doug Bower said this incident was the inspiration for the crop circles he created in England.