Does somebody help me?. My mom who is a U.S citizen. She immigrated in New York for 20 years ago. She wants to request a copy of a record that list all her member relatives who are still living back in Vietnam. She had declared the record some days before she came and lived in America. Now, she wants to sponsor them to come and live in the U.S, but she forgot how many family members whom she had listed in the record. What should she do to get the copy of the record back from more than 20 yrs ago?

Thank you very much. I appreciate your help.