Perhaps you should try some spelling variations:
"nguyen khach quoc." » "nguyen khac quoc." (Expand Search), "nguyen thach quoc." (Expand Search), "nguyen khai quoc." (Expand Search)
"nguyen khanh quoc." » "nguyen khac quoc." (Expand Search), "nguyen anh quoc." (Expand Search), "nguyen manh quoc." (Expand Search), "nguyen hanh quoc." (Expand Search), "nguyen han quoc." (Expand Search), "nguyen khanh ngoc." (Expand Search)
"nguyen thanh quoc." » "nguyen thi quoc." (Expand Search), "nguyen hanh quoc." (Expand Search), "nguyen tranh quoc." (Expand Search), "nguyen thanh nuoc." (Expand Search)

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("nguyen khach quoc.") OR ((("nguyen khanh quoc.") OR ("nguyen thanh quoc."))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"nguyen khach quoc.\") OR (((\"nguyen khanh quoc.\") OR (\"nguyen thanh quoc.\"))))".
• Removing quotes may allow a broader search: (( nguyen khach quoc. ) OR ((( nguyen khanh quoc. ) OR ( nguyen thanh quoc. )))).
• Adding a wildcard symbol may retrieve word variants: (("nguyen khach quoc.") OR ((("nguyen khanh quoc.") OR ("nguyen thanh quoc."))))*.