In Citations and Your Credibility, construction site expert witness William Gulya, Jr., President & CEO, Middlesex Trenching Company writes:
The primary purpose of a citation is intellectual honesty — to attribute to other authors the ideas they have previously expressed, rather than give the appearance to the reader it is the author’s original ideas. The forms of citations generally subscribe to one of the generally accepted citations systems, such as the Harvard or APA (American Psychological Association). Both of these citation systems have their respective advantages and disadvantages relative to the tradeoffs of being informative but not too disruptive. In my opinion, the APA is generally acceptable for expert reports, but either would be completely acceptable.