Turbo, probably grossly delayed, but you can get your docs authenticated at the U.S. consulate / embassy. However, you will need to get your certified divorce decree AND a vital statistics letter + an affidavit saying that you are single. You will have to get those from the source. I ordered mine online and had them delivered, so I didn't have to fly back to the U.S. to get those papers.
From there, it was simply getting them all translated to Vietnamese using a certified translator.