Full-text psychology and behavioral sciences journal articles
Other useful article databases for psychology research:
Coverage in key subject areas such as, biology, chemistry, criminal justice, economics, environmental science, history, marketing, political science, and psychology with full-text articles from periodicals covered in major bibliographic resources such as CINAHL, BIOSIS, MLA, PsycINFO, ERIC, EconLit, RILM, and others.
Google's academic search engine accesses a wide range of academic articles, books and other documents.
To search for multiple concepts, use ORs between words for the same concept, quotes around phrases, parentheses around each concept, and ANDs between concepts, e.g. (study OR research) AND ("child development") AND ("single mother" OR "single parent" OR "single father")