Global-scale surface spectral variations on Titan seen from Cassini/VIMS - Barnes, Jason W.; Brown, Robert H.; Soderblom, Laurence; Buratti, Bonnie J.; Sotin, Christophe; Rodriguez, Sebastien; Le Mouèlic, Stephane; Baines, Kevin H.; Clark, Roger; Nicholson, Phil (ICARUS, 2007)