Vay, S., S.C. Tyler, Y. Choi, D.R. Blake, N.J. Blake, G.W. Sachse, G.S. Diskin, and H.B. Singh (2009), Sources and Transport of Δ14C in CO2 within the Mexico City Basin and vicinity, Atmos. Chem. Phys., 9, 4973-4985.