http://www.policeone.com/edged-weapons/articles/102828-Edged-Weapon-Defense-Is-or-was-the-21-foot-rule-valid-Part-1/ http://www.policeone.com/edged-weapons/arti

http://www.policeone.com/edged-weapons/articles/102828-Edged-Weapon-Defense-Is-or-was-the-21-foot-rule-valid-Part-1/ http://www.policeone.com/edged-weapons/articles/102828-Edged... http://en.wikipedia.org/wiki/Tueller_Drill http://en.wikipedia.org/wiki/Tueller_Drill