Start your citation with: "American Psychiatric Association." This is the group that puts together and publishes the DSM-IV-TR
Add the date last revised in parenthesis, followed by a period.
Add the full title of the publication in italics. Directly after the title add the addition number; you must also mention that the text is a revised edition. This should be formatted as: (4th ed., text rev.) and have a period after the closing parenthesis.
Add the publishing city, which is Washington, D.C. and follow that with a period.
Double space your citation and indent the second line of your citation.