Supporting high-dpi pixel-dense "Retina" Displays like iPhones or the iPad 3 with CSS or IMG - Scott Hanselman's Blog
Retina display Macs, iPads, and HiDPI: Doing the Math (updated) | Engadget
Retinal pathology in experimental optic neuritis is characterized by retrograde degeneration and gliosis | Acta Neuropathologica Communications | Full Text
Mac external displays for designers and developers, part 2
Getty Images | Optimizing Your Images For Retina Displays
Designer's guide to DPI
Retina display Macs, iPads, and HiDPI: Doing the Math (updated) | Engadget
Intel Looking Toward Retina Display PCs by 2013 - MacRumors