1. H. S. Washington, “Chemical Analyses of Igneous Rocks Published from 1884 to 1913,” Prof. Paper 99, U.S.G.S. 1917, pp. 1201.
2. Osann-Rosenbusch, Gesteinslehre, fourth edition, 1923, p. 113.
3. Daly, Igneous Rocks and Their Origin, 1914, p. 25.
4. G. W. Tyrrell. “Classification and Age of the Analcite-bearing Igneous Rocks of Scotland,” Geol. Mag., lx, 1923, pp. 249–60.
5. N. L. Bowen, “The Origin of Anorthosite,” Journ. Geol., 25, 1917, pp. 209–43.