Perhaps you should try some spelling variations:
"nguyen quang quoc." » "nguyen xuan quoc." (Expand Search), "nguyen quang duoc." (Expand Search), "nguyen quang truoc." (Expand Search), "nguyen hoang quoc." (Expand Search)
"nguyen tran quoc." » "nguyen trai quoc." (Expand Search), "nguyen tan quoc." (Expand Search), "nguyen thanh quoc." (Expand Search)
"nguyen tuan quoc." » "nguyen xuan quoc." (Expand Search), "nguyen thanh quoc." (Expand Search), "nguyen tien quoc." (Expand Search), "nguyen toan quoc." (Expand Search), "nguyen chuan quoc." (Expand Search), "nguyen tuan truoc." (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 tran quoc.") OR ((("nguyen tuan quoc.") OR ("nguyen quang quoc."))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"nguyen tran quoc.\") OR (((\"nguyen tuan quoc.\") OR (\"nguyen quang quoc.\"))))".
• Removing quotes may allow a broader search: (( nguyen tran quoc. ) OR ((( nguyen tuan quoc. ) OR ( nguyen quang quoc. )))).
• Adding a wildcard symbol may retrieve word variants: (("nguyen tran quoc.") OR ((("nguyen tuan quoc.") OR ("nguyen quang quoc."))))*.