The following examples illustrate the name–year system. In this system (sometimes called the Harvard system), in-text references consist of the surname of the author or authors and the year of publication of the document. End references are unnumbered and appear in alphabetical order by author and year of publication, with multiple works by the same author listed in chronological order.
Each example of an end reference is accompanied here by an example of a corresponding in-text reference. For more details and many more examples, see Chapter 29 of Scientific Style and Format.