BibTex format
@article{Graven:2013:10.1126/science.1239207,
author = {Graven, HD and Keeling, RF and Piper, SC and Patra, PK and Stephens, BB and Wofsy, SC and Welp, LR and Sweeney, C and Tans, PP and Kelley, JJ and Daube, BC and Kort, EA and Santoni, GW and Bent, JD},
doi = {10.1126/science.1239207},
journal = {SCIENCE},
pages = {1085--1089},
title = {Enhanced Seasonal Exchange of CO<sub>2</sub> by Northern Ecosystems Since 1960},
url = {http://dx.doi.org/10.1126/science.1239207},
volume = {341},
year = {2013}
}