1. Abdel-Monem, A.A.: K-Ar Geochronology of volcanism on the Canary Islands. Unpub. Ph.D. thesis, Columbia University 1969
2. Akella, J., Boyd, F.G.: Partitioning of Ti and Al between coexisting silicates, oxides and liquids. Proceed. Fourth Lunar Sci. Conf. Suppl. 4, Geochim, Cosmochim. Acta 1, 1049?1059 (1973)
3. Armstrong, R.L.: A model for the evolution of strontium and lead isotopes in a dynamic earth. Rev. Geophys. 6, 175?199 (1968)
4. Cooper, J.A., Richards, J.R.: Lead isotopes and volcanic magmas. Earth Planet. Sci. Lett. 1, 259?269 (1966)
5. Cox, K.G., Gurney, J.J., Harte, B.: Xenoliths from the Matsoku pipe. In: Lesotho Kimberlites, (P.H. Nixon, ed.), p. 76?100. Capetown Lesotho: National Development Corporation 1973