@article{Luo2004, author = {Luo, Z.C. and Wilkins, R. and Kramer, M.S.}, title= {Disparities in pregnancy outcomes according to marital and cohabitation status}, year = {2004}, doi = {10.1097/01.AOG.0000128070.44805.1f}, journal = {Obstetrics and Gynecology}, volume = {103}, number = {6}, pages = {1300--1307}, }