@article{Kramer1988,
author = {Kramer, M.S. and McLean, F.H. and Boyd, M.E. and Usher, R.H.},
title= {The Validity of Gestational Age Estimation by Menstrual Dating in Term, Preterm, and Postterm Gestations},
year = {1988},
doi = {10.1001/jama.260.22.3306},
journal = {Journal of the American Medical Association},
volume = {260},
pages = {3306--3308},
}