Khoi Vinh; Mark Boulton. <a href="http://www.subtraction.com/pics/0703/grids_are_good.pdf"><cite>Grids Are Good.</cite></a> March 2007. SXSW Interactive, Austin, TX. URL: <a href="http://www.subtraction.com/pics/0703/grids_are_good.pdf">http://www.subtraction.com/pics/0703/grids_are_good.pdf</a>