Darwin, C., Barrett, P. H., & Freeman, R. B. (1986). The geology of the voyage of H. M. S. beagle, Pt. 2: Geological observations on the volcanic islands. Pickering.

Darwin, Charles, Paul H. Barrett, and R. B. Freeman. The Geology of the Voyage of H. M. S. Beagle, Pt. 2: Geological Observations on the Volcanic Islands. London: Pickering, 1986.

Darwin, Charles, et al. The Geology of the Voyage of H. M. S. Beagle, Pt. 2: Geological Observations on the Volcanic Islands. Pickering, 1986.