The abundances of constituents of Titan's atmosphere from the GCMS instrument on the Huygens probe. - Niemann HB; Atreya SK; Bauer SJ; Carignan GR; Demick JE; Frost RL; Gautier D; Haberman JA; Harpold DN; Hunten DM; Israel G; Lunine JI; et al. (Nature, 2005)