James Mallet: Perspectives Poulton, Wallace and Jordan: How discoveries in Papilio butterflies led to a new species concept 100 years ago. In: Systematics and Biodiversity. Band1, Nr.4, 2004, S.441–452, doi:10.1017/s1477200003001300.
Luis Rivas: A Reinterpretation of the Concepts “Sympatric” and “Allopatric” with Proposal of the Additional Terms “Syntopic” and “Allotopic”. In: Systematic Biology. Band13, Nr.1-4, 1964, S.42–43, doi:10.2307/sysbio/13.1-4.42.
Benjamin M. Fitzpatrick, James A. Fordyce, Sergey Gavrilets: What, if anything, is sympatric speciation? In: Journal of Evolutionary Biology. Band21, Nr.6, 2008, S.1452–1459, doi:10.1111/j.1420-9101.2008.01611.x, PMID 18823452.
Benjamin M. Fitzpatrick, James A. Fordyce, Sergey Gavrilets: What, if anything, is sympatric speciation? In: Journal of Evolutionary Biology. Band21, Nr.6, 2008, S.1452–1459, doi:10.1111/j.1420-9101.2008.01611.x, PMID 18823452.