Attachment Theory is a psychological theory used in psychology, social work, and other behavioral health disciplines.

For an overview of the theory and theorists for it, use an encyclopedia like Gale Virtual Reference Library, or Encyclopedia of Social Work.

For articles about how attachment theory has been used or applied, search an appropriate research database for "attachment theory" plus whatever population or issue you're interested in researching out. You can find a list of commonly-used psychology and behavioral health databases here.