@misc{misc98cd51a9, title = {Factors Associated with preterm births in southeast Brazil: a comparison of two births cohorts born 15 years apart}, author = {Bettiol, Heloisa and Rona, Roberto J. and Chinn, Susan and Goldani, Marcelo Zubaran and Silva, Antonio A. M. and Barbieri, Marco Antonio}, year = {1999}, booktitle = {Annual Meeting of the Pediatric and Academic and Societies} }