Before revision: colspan=" 4 " | Light Bulbs"Lighting Ergonomics - General" by Canadian Centre for Occupational Health & Safety, CCOHS, January, 2003, retrieved November 3, 2007 |- style="height:35px" align="center" !
After revision: colspan=" 5 " | Light Bulbs"Lighting Ergonomics - General" by Canadian Centre for Occupational Health & Safety, CCOHS, January, 2003, retrieved November 3, 2007 |- style="height:35px" align="center" !