Rieder, R.; Wänke, H.; Economou, T.; Turkevich, A. (1 February 1997). "Determination of the chemical composition of Martian soil and rocks: The alpha proton X ray spectrometer". Journal of Geophysical Research: Planets. 102 (E2): 4027–4044. Bibcode:1997JGR...102.4027R. doi:10.1029/96je03918. ISSN0148-0227.
Rieder, R.; Wänke, H.; Economou, T.; Turkevich, A. (1 February 1997). "Determination of the chemical composition of Martian soil and rocks: The alpha proton X ray spectrometer". Journal of Geophysical Research: Planets. 102 (E2): 4027–4044. Bibcode:1997JGR...102.4027R. doi:10.1029/96je03918. ISSN0148-0227.
Rieder, R.; Wänke, H.; Economou, T.; Turkevich, A. (1 February 1997). "Determination of the chemical composition of Martian soil and rocks: The alpha proton X ray spectrometer". Journal of Geophysical Research: Planets. 102 (E2): 4027–4044. Bibcode:1997JGR...102.4027R. doi:10.1029/96je03918. ISSN0148-0227.