There are a number of systems used for referencing. In this university the most common is the Harvard system (covered here in a comprehensive set of web pages). This used in many of the Humanities Colleges.
The maths department and some science departments use the Vancouver system.
TESOL, The School of Psychology and the Business School use APA.
other useful documents here:
quick guide to APA
alternative guide to Vancouver
quick guide to Harvard
last updated 13/10/15