Where you look depends on your disciplinary area/content of your research question and the publication type you seek.
A collection of databases that contain independent evidence to inform healthcare decision-making. Includes Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews, Cochrane Central Register of Controlled Trials, Cochrane Database of Methodology Reviews, Cochrane Methodology Register, Health Technology Assessment Database, and NHS Economic Evaluation Database.
Provides access to abstracts of articles, books and dissertations in the psychological, social and behavioral sciences. Produced by the American Psychological Association.
PubMed and Ovid's MEDLINE both offer tools for searching MEDLINE, the National Library of Medicine’s database for journal articles in life sciences with a concentration on biomedicine.