@article{Hudman_2008,
title={Biogenic versus anthropogenic sources of CO in the United States},
volume={35},
ISSN={1944-8007},
url={http://dx.doi.org/10.1029/2007gl032393},
DOI={10.1029/2007gl032393},
number={4},
journal={Geophysical Research Letters},
publisher={American Geophysical Union (AGU)},
author={Hudman,
R. C. and Murray,
L. T. and Jacob,
D. J. and Millet,
D. B. and Turquety,
S. and Wu,
S. and Blake,
D. R. and Goldstein,
A. H. and Holloway,
J. and Sachse,
G. W.},
year={2008},
month=feb }