Several USCIS publications and resources are available in other languages. See below for a list of materials available in Vietnamese.
Official list of civics questions and answers for the naturalization test.
If an applicant is age 65 or older and has been a permanent resident for at least 20 years at the time of filing for naturalization, he or she should study this list of questions and answers.
6" x 9" informational flyer in Vietnamese.