Phillips, D., and T.C. Onstott. 1988. “Argon Isotopic Zoning in Mantle Phlogopite”. Geology 16: 542-46. doi:10.1130/0091-7613(1988)016<0542:AIZIMP>2.3.CO;2. Reference Link
Agrella-Filho, M.S. D, I.I.G. Pacca, R.I.F. Trindade, W. Teixeira, M.I.B. Raposo, and T.C. Onstott. 2004. “Paleomagnetism and 40Ar 39Ar Ages of Mafic Dikes from Salvador (Brazil): New Constraints on the São Francisco Craton APW Path Between 1080 and 1010 Ma”. Precambrian Research 132: 55-77. doi:10.1016/j.precamres.2004.02.003. Reference Link