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Husson, D., Galbrun, B., Laskar, J., Hinnov, L. A., Thibault, N., Gardin, S., & Locklair, R. E. (2011). “Astronomical calibration of the Maastrichtian (late Cretaceous)”. Earth and Planetary Science Letters305 (3): 328–340. Bibcode: 2011E&PSL.305..328H. doi:10.1016/j.epsl.2011.03.008.