Kiefer, Walter S. (30 Μαΐου 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. doi:10.1016/j.epsl.2004.03.009. Bibcode: 2004E&PSL.222..349K.
Kiefer, Walter S. (30 Μαΐου 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. doi:10.1016/j.epsl.2004.03.009. Bibcode: 2004E&PSL.222..349K.