@article{liao_huang_wang_fan_2019,  title={Association of Surfactant-Associated Protein D Gene Polymorphisms with the Risk of COPD: a Meta-Analysis},  volume={74},  ISSN={1807-5932},  url={https://doi.org/10.6061/clinics/2019/e855},  DOI={10.6061/clinics/2019/e855},  journal={Clinics},  publisher={Faculdade de Medicina / USP},  author={Liao, Yi and Huang, ChengLiang and Wang, JianRong and Fan, XianMing},  year={2019},  pages={e855} }