Russia loses 2012 Olympic silver in women's 4×400 relay

OLYMPIC TRACK: US women win 4×400 to give Felix 3rd gold – The

Felix's 11th medal comes in US runaway in 4x400 hurdles

OLYMPICS UPDATE — US women win 4x400 to give Felix 3rd Olympic

Russia stripped of silver medal in 2008 Olympic relay as athletes

I feel at peace': Allyson Felix exits stage with record 11th medal

USA Win 4x400m Relay Gold - London 2012 Olympics

I feel at peace': Allyson Felix exits Olympic stage with record 11th

Olympic javelin silver medallist among four athletes sanctioned by

4 × 100 metres relay - Wikipedia

Two Americans break previous women's 400m hurdles world record