Voyager 1 and 2: Atlas of Six Saturnian Satellites, NASA SP-474
NASA
1984
<a rel="nofollow" class="external free" href="http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840027171_1984027171.pdf">http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840027171_1984027171.pdf</a>