Irwin, Darren E.; Irwin, Jessica H.; Price, Trevor D. (2001). "Ring species as bridges between microevolution and speciation". Genetica. 112/113: 223–243. doi:10.1023/A:1013319217703. PMID11838767.
nih.gov
pubmed.ncbi.nlm.nih.gov
Irwin, Darren E.; Irwin, Jessica H.; Price, Trevor D. (2001). "Ring species as bridges between microevolution and speciation". Genetica. 112/113: 223–243. doi:10.1023/A:1013319217703. PMID11838767.