Barton, N. H. (2013). Differentiation. In Encyclopedia of Biodiversity (2nd ed., pp. 508–515). Elsevier.https://doi.org/10.1016/b978-0-12-384719-5.00031-9 
LibreCat: https://research-explorer.ista.ac.at/record/10899
DOI: 10.1016/b978-0-12-384719-5.00031-9