Oberon

http://www.planetary.org/multimedia/space-images/uranus/uranus-moons-voyager-2-high-resolution.html

http://www.planetary.org/multimedia/space-images/uranus/voyager-2-s-images-of-uranian-moons.html

http://www.planetary.org/multimedia/space-images/charts/the-moons-of-uranus-to-scale.html

http://www.planetary.org/blogs/emily-lakdawalla/2009/1815.html