\usepackage{url}
@article{ mujicaparodi:plosone_2009,
    author={Mujica-Parodi, L. and Strey, H. and Frederick, B. and Savoy, R. L. and Cox, D. D. and Botanov, Y. and Tolkunov, D. and Rubin, D. and Weber, J.},
    title={{Chemosensory Cues to Conspecific Emotional Stress Activate the Amygdala in Humans}},
    journal={PLoS One},    
    volume={4},
    number={7},
    pages={e6415},
    
    url={http://www.rowland.harvard.edu/cox/pdfs/journal.pone.0006415.pdf},
    year={2009}
}