If a DOI (Digital Object Identifier) exists for a publication, the APA style manual requires that it be included at the end of the citation in the reference list. Sometimes DOIs are listed in the article databases, but not always. To doublecheck whether or not a DOI exists, use this search feature at crossref.org.
Citation managers collect and organize citations, and help you create reference lists.
The Metro State Library supports Zotero, an open source citation manager. To learn more, and for assistance in setting it up, visit our Zotero guide.