Generally, when using the MLA style a reference in your paper requires only the name of the author (or authors) and the page number (with no punctuation between the two items).

References should be, whenever possible, placed at the end of a sentence (before the concluding punctuation). For example:

Alternatively, the author's surname may be integrated into the text, followed immediately by page number(s) in brackets.

If you need to reference a work written by four or more authors, write the first author's name followed by et al.

If there is more than one reference by an author in the same year they are generally labelled in order of publication with a lower case letter (e.g. 1992a, 1992b).

If the author's name is unknown you should give a shortened title of the article, book or webpage.

You may want to refer to a work that you haven't actually read but which has been summarised or discussed in somebody else's work.

In the list of references at the end of your work only include the reference where you have read about the original work. You cannot include details about the original study as you have not read it.