1. F. H. Lahee, Field Geology, 2nd ed., 1923, pp. 18–20; W. A. Richardson, “Petrography of the Marlstone Ironstone of Leicestershire,” Trans. Inst. Min. Eng., lx, pt. 4, 21, pp. 337–44.
2. E. Hatschek, Introduction to the Physics and Chemistry of Colloids, 1918; A. Holmes, Nomenclature of Petrology, 1920, pp. 63–4; P. Niggli, Lehrbuch d. Min., 1921, pp. 430–45; D. Hubbard. Hatschek, Introduction to the Physics and Chemistry of Colloids, 1918; A. Holmes, Nomenclature of Petrology, 1920, pp. 63–4; P. Niggli, Lehrbuch d. Min., 1921, pp. 430–45; D. Hubbard, “Colloids in Geologic Problems,” Amer. Journ. Sci., 4, 1922, pp. 95–110; A. Scott, “The Application of Colloid Chemistry to Mineralogy and Petrology,” Rept. Brit. Assoc. Adv. Sci., 1922, pp. 204–43.
3. J. Johnston and E. D. Williamson, “Rôle of Inorganic Agencies in the Deposition of Calcium Carbonate,” Journ. Geol., 24, 1916, pp. 729–50.
4. J. W. Gregory, “Constructive Waterfalls,” Scott. Geogr. Mag., 27, 1911, pp. 537–46.
5. K. Hummel, “Die Enstehung eisenreicher Gesteine durch Halmyrolyse,” Geol. Rundschau, 13, 1922, pp. 41–81; 97–136.