"Dual Sport Touring Z Drag Recovery Rope System Kit Dual Pulley." Dual Sport Touring Z Drag         Recovery Rope ZDRAG. N.p., n.d. Web. 30 Nov. 2016.

Cox, Steven M., and Kris Fulsaas. Mountaineering: The Freedom of the Hills. Seattle, WA: Mountaineers, 2003. Print.

Physics for Sci & Engrg w/Mod Physics 3rd Ed., Knight

"How Do Pulleys Work? | How Do Pulleys Increase Lifting Force?" Explain That Stuff. N.p., 29  May 2016. Web. 30 Nov. 2016.

"How to Get into Ski Touring: Essential Gear." Backcountry.com. N.p., n.d.         Web. 30 Nov. 2016. (Ski Touring Photo)

PBS. PBS, n.d. Web. 30 Nov. 2016. (self arrest photo)

"Self-arrest in Snow." Mountaineering Methodology. N.p., n.d. Web. 30 Nov. 2016.