Dr.Mark Hamer's study on the psychological impact of second-hand tobacco smoke appears in the Archives of General Psychiatry, a journal published by the American Medical Association.

VOA: standard.2010.06.15

Three other moments of silence were observed - at 0903, 0959 and 1029 - reflecting the second impact and the fall of the skyscrapers.

BBC: NEWS | Americas | US marks three years since 9/11

The second captures the performance impact of sales growth or retrenchment.

FORBES: The Right Way to Measure Performance

The second negative impact is on Ireland itself.

FORBES: The Celtic Comeback? Don't Believe the Hype