Bramer, W. M., Rethlefsen, M. L., Kleijnen, J., & Franco, O. H. (2017). Optimal database combinations for literature searches in systematic reviews: a prospective exploratory study. Systematic reviews, 6(1), 245. doi:10.1186/s13643-017-0644-y
These are commonly used databases for systematic reviews. Depending on your research question, you might want to consider other databases.