Estimation of the fossil fuel component in atmospheric CO2 based on radiocarbon measurements at the Beromünster tall tower, Switzerland - Berhanu, T. A.; Szidat, S.; Brunner, D.; Satar, E.; Schanda, R.; Nyfeler, P.; Battaglia, M.; Steinbacher, M.; Hammer, S.; Leuenberger, M. (Atmos. Chem. Phys., 2017)