Calvignac, S.; Hughes, S. Ancient DNA evidence for the loss of a highly divergent brown bear clade during historical times. Molecular Ecology. 1998, 17 (8): 1962–1970. PMID 18363668. doi:10.1111/j.1365-294x.2008.03631.x.
Calvignac, S.; Hughes, S. Ancient DNA evidence for the loss of a highly divergent brown bear clade during historical times. Molecular Ecology. 1998, 17 (8): 1962–1970. PMID 18363668. doi:10.1111/j.1365-294x.2008.03631.x.
toothandclaw.org.uk
Brown Bear. Tooth & Claw. [2008-01-05]. (原始内容存档于2007-12-23).
web.archive.org
Brown Bear. Tooth & Claw. [2008-01-05]. (原始内容存档于2007-12-23).