The IEEE style is a numeric style, where in-text citations are numbered in order of appearance and that number is enclosed in square brackets, i.e. [1]. The number given to an in-text citation is also given to the complete reference in the list of references at the end of your work. Each source should be numbered according to the order in which they appear in your work. When a source has been cited once, the same number is re-used for all subsequent citations for the same source.
Cite Them Right Online for IEEE. Incudes how to reference items using the IEEE style and general guidance on paraphrasing and secondary referencing.
Guidance about how to use the IEEE referencing style is available in this IEEE Referencing Guide.
