@article{barros_1999,  title={Child-care attendance and common morbidity: evidence of association in the literature and questions of design},  volume={33},  ISSN={0034-8910},  url={https://doi.org/10.1590/S0034-89101999000100013},  DOI={10.1590/S0034-89101999000100013},  number={1},  journal={Revista de Saúde Pública},  publisher={Faculdade de Saúde Pública da Universidade de São Paulo},  author={Barros, Aluísio J. D.},  year={1999},  month={Feb},  pages={98–106} }