Cita APA (7th ed.)
Lyell, C., & Rudwick, M. J. S. (1991). Principles of geology. University of Chicago Press.
Cita Chicago (17th ed.)
Lyell, Charles, i M. J. S. Rudwick. Principles of Geology. Chicago: University of Chicago Press, 1991.
Cita MLA (9th ed.)
Lyell, Charles, i M. J. S. Rudwick. Principles of Geology. University of Chicago Press, 1991.
Atenció: Aquestes cites poden no estar 100% correctes.