Search for organic and volatile inorganic compounds in two surface samples from the chryse planitia region of Mars - Biemann, K.; Oro, John; Toulmin III, P.; Orgel, Leslie; Nier, A.O.; Anderson, D.M.; Simmonds, P.G.; Flory, D.; Diaz, A.V.; Rushneck, D.R.; Biller, J.A. (Science, 1976)