For an electronic fulltext version of a print journal article , the citation elements you need are the same as for a print journal article, plus the access path or database name and the date you accessed, printed, or downloaded the article. Cockburn, Alexander. 1999. The Headwaters Deal. Selections from the Federal Theatre Project 1935-1939. Citations follow standardized rules for arranging the citation elements.
Style manuals are books that explain the rules for citations.
The first two examples above use the rules in A Manual for Writers of Term Papers, Theses, and Dissertations , by Kate Turabian. This and other style manuals are in the UNLV Libraries. Most disciplines have a preferred style manual. You may have been told which style manual to use. If not, ask your instructor.