Reference: Transactions of the International Astronomical Union, Moscow, August 12-20, 1958: Cambridge University Press, v. 10, pl. 1, p. 262. 259-63; A. Dollfus: Visual and photographic studies off planets at the Pic du Midi. In: Planets and Satellites, GP Kuiper and B Middlehurst, eds. Chicago Univ Press 543-571; Richardson-Bonestell Mars 1964