Published research in engineering uses two main citation styles: IEEE and ASCE (author-date). Below are links to several sites that provide directions and samples for each style. Please be sure you remain consistent when documenting your sources; in other words, pick one style and stick with it. Do not use MLA; though you are probably most familiar with that style, it is meant for research in the humanities. 

University of Toronto IEEE Guide

IEEE Editorial Style Manual

University of Melbourne Guide to ASCE

University of Canterbury Guide to ASCE