“The foundations of The origin of species, a sketch written in 1842“. Charles Darwin, ed. 1909.
“The foundations of The origin of species. Two essays written in 1842 and 1844“. Charles Darwin, F. ed. 1909.
“On the tendency of species to form varieties; and on the perpetuation of varieties and species by natural means of selection“. Charles Darwin and Alfred Russel Wallace, 1858.
On the Origin of Species. Charles Darwin, 1859.
