Sewell, Stephen ‘Cookie’ (1998). Why Three tanks? in Armor vol 108, no 4, p 21. Fort Knox, KY US Army Armor Center. 存档副本(PDF). [2008-09-29]. (原始内容(PDF)存档于2007-06-28)..
Sewell, Stephen ‘Cookie’ (1998). Why Three tanks? in Armor vol 108, no 4, p 21. Fort Knox, KY US Army Armor Center. 存档副本(PDF). [2008-09-29]. (原始内容(PDF)存档于2007-06-28)..