Version is the fifth core element. It is not always needed. If different versions of the source exist, use this element to state which version is being cited. Some examples of different versions include editions, director's cuts, and abridged or unabridged versions.
Edition:
Howard, Rebecca Moore. "Avoiding Sentence Fragments." Writing Matters: A Handbook for Writing and Research, 2nd ed., McGraw Hill, 2014, pp. 600-10.
Abridged/unabridged:
Sewell, Anna. Black Beauty. Unabridged version, F. M. Lupton, 1877.
Director's cut:
Scott, Ridley, director. Alien. 1979. Performance by Sigourney Weaver, director's cut, Twentieth Century Fox, 2004.