A DOI (digital object identifier) is a unique alphanumeric string that identifies a specific article and provides a persistent link to its location on the Internet.
When DOIs are available include them in your citation. DOIs can be available for both print and electronic sources. The DOI is typically located on the first page of the journal article, near the copyright notice or in the bibliographic record in the database.
"This database is the APA's renowned resource for abstracts of scholarly journal articles, book chapters, books and dissertations. It is the largest resource devoted to peer-reviewed literature in behavioral science and mental health, with ninety-nine percent of the covered material peer-reviewed."
