Kiefer, Walter S. (30-05-2004). "Gravity evidence for an extinct magma chamber beneath Syrtis Major, Mars: a look at the magmatic plumbing system". Earth and Planetary Science Letters222 (2): 349– 361. Bibcode:2004E&PSL.222..349K. doi:10.1016/j.epsl.2004.03.009.
Kiefer, Walter S. (30-05-2004). "Gravity evidence for an extinct magma chamber beneath Syrtis Major, Mars: a look at the magmatic plumbing system". Earth and Planetary Science Letters222 (2): 349– 361. Bibcode:2004E&PSL.222..349K. doi:10.1016/j.epsl.2004.03.009.