A reference must provide the name of the authors, the year, the title and information on the source. The APA style, by the American Psychological Association, is a bibliographic style used in many fields of study. Always verify with your professor if he or she has any other bibliographic style requirement.
An author may be : an individual, multiple people, a group (institution, government, organizations, etc.) or a combination of people and groups.
The year refers to the year of publication. Do not provide a year in the reference if the document is not published yet.
The source indicates where readers can retrieve the cited work. Items vary depending on the type of document.
The source elements are separated by a comma and the period ends the reference.
Here is the information that must be provided for the source :
Article : journal, volume(number), pages of the article. DOI (if available).
Edited book chapter and Reference work: In editor (Ed.), book title (edition, page range). Publisher.