RT Journal Article SR Electronic T1 Late Date for Siberian Site Challenges Bering Pathway JF Science JO Science FD American Association for the Advancement of Science SP 450 OP 451 DO 10.1126/science.301.5632.450 VO 301 IS 5632 A1 Stone, Richard YR 2003 UL http://science.sciencemag.org/content/301/5632/450.abstract AB