Banks, Maria E., Byrne, Shane, Galla, Kapil, McEwen, Alfred S., Bray, Veronica J., Dundas, Colin M., Fishbaugh, Kathryn E., Herkenhoff, Kenneth E., and Murray, Bruce C. 2010. "Crater Population and Resurfacing of the Martian North Polar Layered Deposits." Journal of Geophysical Research. E. Planets, 115 E08006.