PMID 12082121. ↑ "A Y Chromosome Census of the British Isles" (PDF). ↑ Leslie, S., Winney, B., Hellenthal, G. et al. The fine-scale genetic structure of the British population. Nature 519, 309–314 (2015). https://doi.org/10.1038/nature14230 1 2 3 Sykes 2006 ↑ Oppenheimer 2006 1 2 3 4 Olalde et al.