1. Wim Hof Method Information
- The IceMan Daredevils Arctic Marathon YouTube
- Wim Hof The Ice Man Cometh YouTube
- The Superhuman World of Wim Hof Doco YouTube
2. Buteyko Institute Method Information
3. Other Relevant Information
- Effects of altering PCO2 levels http://www.ncbi.nlm.nih.gov/pubmed/25122497
