@article{doi:10.1001/jama.1929.92700340003014b,
author = {Manning WJ},
title = {MEthod of positive shadow differentiation},
journal = {Journal of the American Medical Association},
volume = {92},
number = {8},
pages = {646},
year = {1929},
doi = {10.1001/jama.1929.92700340003014b},
URL = { + http://dx.doi.org/10.1001/jama.1929.92700340003014b},
eprint = {/data/Journals/JAMA/6645/jama_92_8_014b.pdf}
}