Lyell, C. (1837). Principles of geology: Being an inquiry how far the former changes of the earth's surface are referable to causes now in operation (1st American from the 5th and last London ed.). J. Kay, jun. & brother; J.I. Kay & Co..
Chicago-referens (17:e uppl.)Lyell, Charles. Principles of Geology: Being an Inquiry How Far the Former Changes of the Earth's Surface Are Referable to Causes Now in Operation. 1st American from the 5th and last London ed. Philadelphia, Pittsburg: J. Kay, jun. & brother; J.I. Kay & Co., 1837.
MLA-referens (8:e uppl.)Lyell, Charles. Principles of Geology: Being an Inquiry How Far the Former Changes of the Earth's Surface Are Referable to Causes Now in Operation. 1st American from the 5th and last London ed. J. Kay, jun. & brother; J.I. Kay & Co., 1837.