Peer-reviewed articles are the most commonly cited academic materials. They are typically published in academic journals, which may be either print- or Web-based. Some Web-based journals do not include page numbers.
Books by one author are among the simplest materials to cite.
Book chapter (or essay in an anthology)
Collective works, which typically include several chapters or essays by various authors on a single theme or topic, are common in academia.
Real-world examples would include the Web versions of the Seattle Times and People.
This is the format you would use if, for example, you were citing material from the online version of the Encyclopedia Britannica.
APA specifies various formats for Web-based materials. The following would only apply if you were citing a basic website, not articles or pages found within a site.