Nikon 20mm f/1.8G ED lens additional coverage - Nikon Rumors
Amazon.com : Sigma 10-20mm f/3.5 EX DC HSM ELD SLD Aspherical Super Wide Angle Lens for Nikon Digital SLR Cameras : Digital Slr Camera Lenses : Electronics
Review of Nikon 20mm f/1.8 G Lens with Sample Photos
Nikon 20mm f/2.8 AI-S Review
Nikon AF-S NIKKOR 20mm f/1.8G ED Lens Preview | ePHOTOzine
Nikon 20mm f/1.8G ED Reviews: Great results from Nikon's latest wide-angle prime - DXOMARK