Darwin, C. R. The origin of species by means of natural selection, or the preservation of favoured races in the struggle for life / by Charles Darwin, M.A., LL.D., F.R.S., etc (Sixth edition, with additions and corrections to 1872. (Twenty-second thousand).).
Cita Chicago Style (17a ed.)Darwin, Charles Robert. The Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life / by Charles Darwin, M.A., LL.D., F.R.S., Etc. Sixth edition, with additions and corrections to 1872. (Twenty-second thousand). London : John Murray, Albemarle street, 1880.
Cita MLA (8a ed.)Darwin, Charles Robert. The Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life / by Charles Darwin, M.A., LL.D., F.R.S., Etc. Sixth edition, with additions and corrections to 1872. (Twenty-second thousand).