IEEE style is mainly used in Electronic and Electrical Engineering and Computer Science, Information Technology, Telecommunication. This number referencing system that includes two elements:
A reference list or end-text citations is the full list of sources you have referred to or cited in the body of your work.
A bibliography is the full list of works that you have used in the preparation of your written work.
A citation or in-text citation is the reference you make to a specific author's work when presenting a specific argument in your own work.
The references include the number of citations, in order of appearance in your paper, in [square brackets].
IEEE style doesn't allow the secondary citation. You have to locate the original source of information otherwise, it should not be cited.
The style allows abbreviations of journal title, months, names of organizations and conferences.