Perhaps you should try some spelling variations:
"nhan vat cua chinh tri vien." » "nhan vat cua chinh tai vien." (Expand Search), "nhan vat cua chinh tri viet." (Expand Search), "nhan vat cua chinh tri chien." (Expand Search), "nhan vat chat chinh tri vien." (Expand Search)
"nhan mat luan chinh tri kien." » "nhan dat luan chinh tri kien." (Expand Search), "nhan hat luan chinh tri kien." (Expand Search), "nhan bat luan chinh tri kien." (Expand Search), "nhan chat luan chinh tri kien." (Expand Search), "nhan luat luan chinh tri kien." (Expand Search), "nhan mat cua chinh tri kien." (Expand Search), "nhan mat luan chinh trien kien." (Expand Search), "nhan mat luan chinh tri kinh." (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: (("nhan vat cua chinh tri vien.") OR ("nhan mat luan chinh tri kien."))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"nhan vat cua chinh tri vien.\") OR (\"nhan mat luan chinh tri kien.\"))".
• Removing quotes may allow a broader search: (( nhan vat cua chinh tri vien. ) OR ( nhan mat luan chinh tri kien. )).
• Adding a wildcard symbol may retrieve word variants: (("nhan vat cua chinh tri vien.") OR ("nhan mat luan chinh tri kien."))*.