Drones give farmers a fresh look at what's happening with their crops. Find out how drones are changing agriculture at HowStuffWorks.
- Halacy, D.S. "How to Build a Solar Still." Mother Earth News.com. 1959. (Accessed April 25, 2011)http://www.motherearthnews.com/print-article.aspx?id=64758.
- SODIS. Solar water Disinfection: Improved Health with Sunlight and PET Bottles. (Accessed April 25, 2011)http://www.sodis.ch/news/material/flyer_poster/flyer_e.pdf.
- Survival Topics. "How to Make a Solar Water Survival Still.". (Accessed April 25, 2011)http://www.survivaltopics.com/survival/how-to-make-a-solar-water-survival-still/.
- "SunSure Water: Clean, Pure Water Produced By the Sun." (Accessed April 25, 2011)http://www.sunsurewater.com/pdfs/Sunsure_brochure.pdf.