Croft, S.K. (1989). New Geologic Maps of the Uranian Satellites Titania, Oberon, Umbriel and Miranda. Proceeding of Lunar and Planetary Sciences. 20. Lunar and Planetary Sciences Institute, Houston. hlm. 205C. Bibcode:1989LPI....20..205C.Parameter |month= yang tidak diketahui akan diabaikan (bantuan)