Science 10 December 2010: 1473. [DOI:10.1126/science.330.6010.1473]
Science-2010-Lawler-Keeping_Watch_as_the_Old_Kingdom_Crumbled-1473.pdf
Science 10 December 2010: 1473. [DOI:10.1126/science.330.6010.1473]
Science-2010-Lawler-Keeping_Watch_as_the_Old_Kingdom_Crumbled-1473.pdf