1. Richey J. E. , 1948. “Scotland. The Tertiary Volcanic Districts”, 2nd ed. revised, Brit. Reg. Geol.
2. Seward A. C. , and Holttum R. E. , 1924. See Mull Memoir.
3. Mull Memoir, 1924. “Tertiary and Post-Tertiary Geology of Mull, Loch Aline, and Oban”, Mem. Geol. Surv. U.K.
4. Zur Mikroscopie der Braunkohlen;Potonie;Braunkohle,1931
5. The Fossil Flora of Tegelen-sur-Meuse, near Venloo in the Province of Limburg;Reid;Verh. Akad. Wet. Amst.,1907