Darwin, Charles, NATURAL SELECTION. CHAP. IV., On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, 1859
Darwin, Charles (1872), The Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life (6th ed.), London: John Murray, ISBN1-4353-9386-4, p. 104
Burki, Fabien; Shalchian-Tabrizi, Kamran & Pawlowski, Jan (2008), "Phylogenomics reveals a new 'megagroup' including most photosynthetic eukaryotes", Biology Letters 4 (4): 366–369, doi:10.1098/rsbl.2008.0224, PMC 2610160, PMID 18522922
Jain R, Rivera MC, Lake JA (1999), "Horizontal gene transfer among genomes: the complexity hypothesis", Proc Natl Acad Sci U S A 96 (7): 3801–6, Bibcode:1999PNAS...96.3801J, doi:10.1073/pnas.96.7.3801, PMC 22375, PMID 10097118
Boucher Y, Douady CJ, Papke RT, Walsh DA, Boudreau ME, Nesbo CL, Case RJ, Doolittle WF (2003). "Lateral gene transfer and the origins of prokaryotic groups". Annu Rev Genet 37: 283–328. doi:10.1146/annurev.genet.37.050503.084247. PMID 14616063
