Below is an introduction to some of the most popular referencing styles and links to examples of referencing guidance documents and tutorials for each of the referencing styles featured.
The IEEE (Institute of Electrical and Electronics Engineers) referencing style is used in engineering disciplines.
The 2009 IEEE style manual contains guidance on referencing and can be viewed as a pdf document here.
A citation reference guide is available here.
The IEEE referencing style refers to The Chicago Manual of Style for guidance on citing any resources that are not covered by the IEEE style manual.
There are free, online guidelines to using the IEEE referencing style including: