An in-text reference should include the authorship, the year of the work and, if applicable, page number(s) to which is being referred.

A reference list of all documents/sources cited in the text is included at the end of the report/paper, in alphabetical order by authorship with date. This reference list will include the full details of the documents. For more information on how to write references for specific documents included in references lists, see Writing references Harvard.

Example:

The structure of the European Union is often described in the shape of three pillars (Tallberg 2004, 65)

You can also reference directly. Example:
Tallberg (2004, 65) describes the structure of the European Union in the shape of three pillars

Book with two or Three Authors

(Fossum, Skantz and Katzeff 1997, 25-31)

or

Fossum, Skantz and Katzeff (1997, 25-31) mean...

Book with four or more Authors

Where there are more than three authors, only the first author should be used, followed by ‘et al.’

(Johnson et al. 2001, 226)

or

Johnson et al. (2001, 226) found that...

Edited Works

Include information about editor in the in-text reference
Example:
(Francis (ed.) 1971, 46)

or

Francis (ed. 1971, 46) showed that...

Material with No Personal Author

If a journal article does not have a personal author, use the title of the article as an in-text reference.

Example:
(Relationship marketing the Chinese way 2000, 21)

Books may also not have a personal author, but organizations, companies, authorities will function as “authors” in those cases. Use standard abbreviations for these organizations etc. in the text, e.g. OECD for Organisation for Economic Co-operation and Development. Provide the full name of the organization in the reference list.
Example:

(OECD 1987, 89)

Several Works by one Author in the Same Uear

If you are quoting several works published by the same author in the same year, they should be separated by adding a lower case letter directly after the year for each item. Please note that the works should be separated the same way in the reference list (by adding a lower case letter after the year).

Example:
Previous results confirmed the thesis (Duncan 2000a, 167-169), but later research disproved it (Duncan 2000b, 40-44).

Web Pages

The same information should be included as for other documents; author, year of publication and, if applicable, page number(s). If there is no personal author, use the corporate author (company, organization, authority etc.).
Examples:
(OECD 2010)
(Volvo 2008)
(Smith 2007, 7)

or

According to OECD (2010)....

Secondary Sources

To cite a source from a secondary source is generally to be avoided, since you are expected to have read the works you cite. If an original source is not available  you may use secondary sources. In those cases mention the original author and date would be used in the text and the text citation would include the words “quoted in.”, see Writing references Harvard. In the example below you have read Bob Smith´s book "Democracy" published 1972 where he on page 67 cites Tom Small´s book "Civil rights" published 1832:

In Tom Small´s book "Civil rights" (quoted in Smith 1972, 67)....

or

(Small 1832, quoted in Smith 1972, 67)