1. L. L. Cavalli-Sforza, and W. F. Bodmer (1971 ). The Genetics of Human Populations , pp.350 -3 . W. H. Freeman.
2. Francis Darwin (1887 ). The Life and Letters of Charles Darwin , vol. 3 , pp.129 -30 . London: John Murray.
3. Population structure in Norway Inbreeding, distance and kinship