@article{doi:10.1001/jama.297.13.1411,
title = {A theory of labor},
journal = {JAMA},
volume = {297},
number = {13},
pages = {1411},
year = {2007},
doi = {10.1001/jama.297.13.1411},
URL = { + http://dx.doi.org/10.1001/jama.297.13.1411},
eprint = {/data/Journals/JAMA/5136/jpm60549_1411_1411.pdf}
}