How do I reference my sources?

There are many systems to reference your source properly. The customs vary from field to field, but there are a few systems that are used often in the social sciences and humanities. The author-date system of the American Psychological Association is the inoffical standard at Twente, because of its use in the Dutch Leren Communiceren handbook.

The basic principle behind referencing system is that it has to be unquivocally clear from what source your information comes, so that the reader can trace it back to the original. In order to achieve this, standard systems have been developed. These prevent you from forgetting bits, but also create a typographically pleasing uniformity. Getting every period, comma, bracket, itallic etc. just right can be a nuisance, but these days, there is software to help you out.

Here's my (very unofficial, but short) overview:

In the text:
(author or organisation, year, p. number).

In the reference list:

Book or report:
Author, Initials. (year). Title. Place: Publisher.

Article:
Author, Initials. (year). Title. Journal, volume (no.), first page-last page.

Chapter in edited book:
Author, Initials. (year). In Editor, Initials (Ed.), Title book (page begin-page end). Place: publisher.

Web pages:
Author or organisation. (year). Title website. Retrieved month, year, from URL.

Other electronic sources, e.g. pdf report:
Author, Initials. (year). Title. Place: Publisher. Retrieved month day, year, from URL.

Examples:

In the text:

(Gilbertson, Holland, Semino, & Smith, 2007, pp. 15-17)

In the reference list:

Gilbertson, T., Holland, N., Semino, S., & Smith, K. (2007). Paving the way for agrofuels: EU policy, sustainability criteria and climate calculations. Amsterdam: Transnational Institute, Corporate Observatory Europe. Retrieved on March 25, 2008, from http://www.tni.org/agrofuels/pavingagrofuels.pdf?.

Stone, D. (2007). Recycling bins, garbage cans or think tanks? Three myths regarding policy analysis institutes. Public Administration, 85(2), 259-278.

Centre for Clean Technology and Environmental Policy. (2008) CSTM webpage. Retrieved March 25, 2008, from http://www.utwente.nl/cstm/.

Common mistakes

Wrong:
http://owl.english.purdue.edu/owl/resource/560/01/

Right:
Neyhart, David en Erin Karper (2008). APA Formatting and Style Guide. http://owl.english.purdue.edu/owl/resource/560/01/. Consulted on 8 February, 2008.

Wrong:
Iles, A. Making seafood sustainable. Science and Public Policy.

Right:
Iles, A. (2004). Making seafood sustainable: merging consumption and citizenship in the United States. Science and Public Policy, 31(2), 127-138.

Further resources