You may come across a source which has a corporate author, where an organisation rather than an individual is responsible for the work. For instance, a government organisation would be cited in the same way as an author, with the organisation name as the author.
Example: (Department of Health, 2013).
Remember: some sources are the result of collaboration between many contributors, none of whom can claim authorship, e.g. dictionaries, encyclopaedias or films. In this case you can use the title in place of the author name, for example: Gone with the Wind.